Thank you for purchasing our products. This manual addresses
the safety guidelines, warranty, and operating instructions. Please
review this manual thoroughly before operating your device.
All pictures in this manual are for illustration purpose only. Actual
product may vary due to product firmware upgrade and app upgrade.
E31
Smart Watch
User Manual
What’s in the Box ....................................................................... 1
Setting up Your Watch ............................................................ 1
1. Disassembling / Assembling Your Watch ..........................1
2. Charging Your Watch .............................................................. 2
Wearing Your Watch.................................................................3
Pair Your Watch ..........................................................................4
1. Install Letsfit App on your smartphone ............................... 4
2. Account Registration and Login ..........................................4
3. Pair the Watch with Your Phone ........................................... 5
App Interfaces..............................................................................7
Getting to Know Your Watch................................................8
Basic Operations ..........................................................................8
Watch Interfaces .......................................................................... 9
Customize the Home Screen ....................................................10
Function Introduction.............................................................10
1. Tracking Daily Activity Data ..................................................12
2. Monitoring Heart Rate............................................................12
3. Measuring Blood Oxygen Level............................................12
4. Tracking Sports .......................................................................13
5. Bluetooth Phone Call..............................................................15
6. Setting Alarms .........................................................................16
7. Message Notification .............................................................16
8. Setting Reminder ....................................................................17
9. Controlling Phone Music .......................................................17
Basic Specifications................................................................
17
FAQs.................................................................................................
18
Warranty.........................................................................................
20
Important Safety Instructions
............................................ 20
Table of Contents
- 1 -
What’s in the Box
Charging cable x 1
Smart watch with bands x 1
Quick start guide x 1
Charging Your Watch
Please fully charge your watch before initial use.
- 2 -
Insert the USB plug of the
charging cable into a USB
charger.
1
Attach the other end to the charging contacts on the
back of the watch. Make sure the pins on the charging
cable lock securely with the port. The connection is
secure when the battery icon with percent charged
appears on the screen.
2
All-day Wear and Exercise
Wearing Your Watch
- 3 -
For all-day wear when you’re not exercising, wear the device
on your wrist horizontally, a finger’s width below your wrist
bone and lying flat, the same way you would put on a watch.
For optimized heart rate tracking, keep these tips in mind:
1. Experiment with wearing the watch higher on your wrist
during exercise. Because the blood flow in your arm increases
the farther up you go, moving the watch up a couple of inches
can improve the heart rate signal. Also, many exercises such
as bike riding or weight lifting require you to bend your wrist
frequently, which is more likely to interfere with the heart rate
signal if the watch is lower on your wrist.
2. Do not wear your watch too tight. A tight band restricts blood
flow, potentially affecting the heart rate signal. This being
said, the watch should also be slightly tighter (snug but not
constricting) during exercise than during all-day wear.
- 4 -
Pair Your Watch
1
Install Letsfit App on your smartphone
2
Account Registration and Login
Please register an account with a valid email address. After
registration, and then tap "Verified" to log in.
Turn on the Bluetooth
of your phone.
1
Settings
Bluetooth
Bluetooth
15
:
05
3
Pair the Watch with Your Phone
Note: The App is only compatible with smartphones, not
tablets or PCs.
You can download Letsfit App from Apple Store /
Google Play or scan the QR codes below to
download.
iOS 12.0 & above Android 6.0 & above
Letsfit
- 5 -
3
Open the Letsfit App.
Go to the "Device" page
and tap "Pair device".
2
15
:
05
Pair device
Two pairing methods
15
:
05
Pair device
Scan QR CodePair by model
Searching...
- 6 -
Notes:
● Once the watch is connected to your app, the watch will
automatically search and reconnect itself if the connection is
lost or when Bluetooth is restarted after manual disconnection.
● If the watch is unbound from the app, the information on the
watch will be reset and the watch will be restarted. Please do
not unbind the connection unless there is an issue that will
require a reset.
● The watch can only pair with one smartphone at a time. When
pairing, please ensure the watch and your smartphone is within
0.5 meters distance.
OR
Tap "Scan QR Code "
and scan the QR code on
the watch to pair.
Tap "Pair by model "
→ "E31-XXXX" to pair.
4
Tap on the watch to
confirm the connection.
Note：
"Bluetooth Pairing
Request" will pop up
twice on your phone,
please click "Pair" both
times.
Pair device
Device found
E31-XXXX
15
:
05
Bluetooth Pairing Request
Pair with “E31-XXXX” ?
Cancel Pair
Pair with this
device?
App Interfaces
- 7 -
Device
After the watch is connected to your
phone, you can customize watch
face / call / message / alarm /
sedentary alert , etc.
Summary
Heart Workout
39/30 MIN
Active Hours
4/6
Weekly goal
39/150 MIN
It’s still 111 minutes away, keep going!
HRS
Steps
5,641/6,000
Activity
Summary
Summary Device More
Edit
Mon, Nov 22
Heart
53-172 BPM
Caiories Burned
668/530 KCAL
Distance
2.8 MI
Today’s data
Swipe down
to sync data.
Tap to view
today’s
activity data.
Select a
date to view
the data.
Workout
39/30 MIN
Active Hours
4 / 6 HRS
Daily Workout Minutes
Daily Active Hours
Daily
Target
Value
Daily Steps
Steps
5,641/6,000
Summary Device More
- 8 -
Getting to Know Your Watch
•
Function Button
● Wake the screen
● Return to the home screen
● Go to the Function List
● Pause / resume the sport
● Power on / off, Reboot,
Reset the watch.
Press
Hold
•
Touch Screen
● Swipe to go to different interfaces.
● Tap to enter the function.
● Swipe the screen to the right to
return to the previous interface.
● Press and hold Home screen to
change watch face.
- 9 -
Notifications
Quick Settings
Blood OxygenHeart Rate
SleepStress
20
200
0
00:00
12:00
24:00
100
0
00:00
12:00
24:00
Swipe
Right/Left
Swipe Down
Swipe Up
Note:
If your phone is an Android phone, only
when your watch is connected to the
Letsfit App, the App is running on your
phone, and "Notification Alerts" is
enabled in the App, will messages be
notified.
- 10 -
After the watch is paired with your
phone, the home screen will display the
time and date.
You can customize the home screen by
following the steps below :
1) Press and hold the watch home
screen for two seconds.
2) Swipe left / right to choose one and
tap to confirm.
Function Introduction
Customize the Home Screen
Press the watch
function button go to
the function list
8000
234 25
- 11 -
Phone
Bluetooth Call(Make
and Answer Call), Call
History.
Health
Check your daily
activities / Heart Rate /
Blood Oxygen / sleep
data /Guides your
breathing, etc.
Clock
Customize your Alarm /
Countdown Timer /
Stopwatch.
Record
View the last 20 sports
records.
Music
Control the music
playing of your
smartphone.
Settings
Some basic settings
and information of
the watch.
Reminders
Set reminders on the
app make the watch
vibrate to remind you.
Weather
The weather forecast for
the next few days. Weather
data is obtained through
your phone’s network.
Connect the watch to your
phone to timely update
weather data.
Flashlight
Turn on the torch light
of your watch.
Workout
Tracks your exercise data
in sports modes. Choose
the mode that you want
to start on the watch.
Message
Check text messages or
social media messages
from your phone.
Find phone
Use the watch to locate
your phone by making
your phone ring.
- 12 -
Note:
To monitor heart rate more accurately, wear the watch on the
upper position of your wrist and a bit tighter than usual when
you exercise. In addition, complete your profile in the app.
2. Monitoring Heart Rate
Tap " Health" and tap “ Heart Rate” in the function list,
the watch will automatically measure your real-time heart rate.
You can also view your all-day heart rate data in the heart rate
interface of the watch or in the app.
3. Measuring Blood Oxygen Level
Tap " Health" and tap “ Blood
Oxygen” to enter the blood oxygen level
detection mode.
1. Tracking Daily Activity Data
Tap " Health" and tap “ Activity”
in the function list.
The watch tracks your all-day activity data,
including steps, distance, calories burned,
etc.
HEALTH 12:30 PM
HEALTH 12:30 PM
200
0
00:00
12:00
24:00
100
0
00:00
12:00
24:00
- 13 -
4. Tracking Sports
The watch tracks your exercise data in
workout modes.
Set goals
Before beginning an exercise, you can tap
“Set Goals” to set training goals such as
time, distance, calories burned.
GPS connecting
(Only for some outdoor sport modes)
When you start an outdoor sport, the watch begins searching
GPS signal. Please let the Letsfit app run in the background and
allow the location services on your phone, then move to an
open area and stand still to better receive the signal. After the
GPS is connected, the countdown interface will be displayed,
and then you can start training.
Set Goals
Start
Start a sport
Tap " Workout" in the function list →
Swipe the screen to select a sports mode
you want to start.
When the GPS signal is weak, you can start outdoor running,
outdoor walking in non-GPS mode. Your movement track will not
be displayed in your training record after the exercise is ended.
Note:
Before measuring, wear the watch two fingers below the wrist bone
and a bit tighter than usual.
When measuring, keep your arm flush with your chest and the
watch screen facing up. Keep your arm still to ensure the accuracy
of the data.
- 14 -
E31
Notes:
● After ending an exercise, you can
view detailed data and graphs in the
app (Go to the "Summary" page,
swipe down the page to synchronize
data, and tap the exercise you just
ended).
● After you finish the outdoor cycling,
outdoor running or outdoor walking
exercise in GPS mode, your
movement track will be displayed in
the app (Go to the "Summary" page
of the app, and then tap on the
exercise you just ended to view).
● Data of exercises less than 1 minutes will not be saved.
● When the battery level is below 10%, please charge the watch
before starting the exercise.
During sports
Swipe the screen up or down to
flip through exercise data.
Swipe the screen to the left so
you can control the music
playing on your phone.
End the sport
Press the function button and
tap “End” to end the sport.
End
Continue
- 15 -
When a call comes in, tap the green phone
icon to answer it, tap the red phone icon to
reject the call, press the watch function button
to ignore the call.
Settings
Bluetooth
Bluetooth
15
:
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E31-XXXX
Connected for calls
5. Bluetooth Phone Call
5.1 Answer incoming calls with your watch
5.2 Make a call from your watch
On your watch, select " Phone"
at the function list.
Tap the “Dial Pad” icon to dial a
number, or tap the “Contacts” icon
to select a specific contact.
When you're ready, tap the green
phone icon to make a call.
PHONE
12:30 PM
Go to the "Device" page in the Letsfit app, tap "Favorite Contacts"
to set favorite contacts.
5.3 Set Favorite Contacts
PHONE
12:30 PM
Helen
Mike
Favorite Contacts Add
15
:
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Helen
XXX XXX XXXX
Mike
XXX XXX XXXX
You can make and answer calls
using the Watch! Just make sure
your watch is connected via
Bluetooth(Connected for calls).
Helen
- 16 -
When messages (like Facebook, Twitter, and
Instagram messages) come in, the watch
vibrates to alert you, and the screen
displays the message content.
Notes:
● Only when "Notification alerts" is enabled in the app
("Device" page → "Notification alerts", turn on "Notification
alerts"), will messages be notified.
● When the "DND" function is enabled in the app ("Device"
page → "Do Not Disturb") or on the watch (Quick settings
bar → ), messages will not be notified on the watch
during the do-not-disturb period.
6. Setting Alarms
You can add/enable/disable the alarm on your watch (Tap
"Clock" → "Alarm"on the watch and then choose to add or turn
on/off the alarm you set.)
7. Message Notification
Notes:
● Only when "Notification alerts" is enabled in the app ("Device"
page → "Notification alerts", turn on "Notification alerts"), will
phone call be notified.
● When the "DND" function is enabled in the app ("Device" page →
"Do Not Disturb") or on the watch (Quick settings bar→ ),
phone call will not be notified on the watch during the
do-not-disturb period.
● "Silent Mode On" can turn off ringtone of the watch.
- 17 -
Basic Specifications
Model No.: E31
Sync: Bluetooth 5.3
Screen: 1.69” TFT LCD
Waterproof Rating: IP68
Working Time: 6-8 days
Input: DC 5V/1A
Battery Capacity: 300mAh
Working Voltage: 5V-500mAh
Working Temperature: -10℃ to 40℃
If you need to set reminders, you can click "Reminders" on the
"Device" page of Letsfit app to set the reminder time and label.
After the watch is connected to your
phone, tap " Music" on the watch to
enter the function and control the music
playing on your phone.
Note:
You can only control the music player
that’s running on your phone.
8. Setting Reminder
9. Controlling Phone Music
Failure to re-pair the watch with the Letsfit app on
your smartphone
1. Swipe up the home screen of watch and tap ” ” and
choose "Reset". The information on the watch will be reset
and the watch will be restarted.
2. Click the "Pair Device" button on the APP and pair the device
by searching for the device model or scanning the QR code on
the watch.
Notes:
1. Make sure your smartphone’s Bluetooth is enabled and make
sure the watch is not connected to other smartphones.
2. Make sure the distance between your smartphone and the
watch does not exceed 0.5 meters and keep the watch screen
always on when pairing.
Occasional failure to connect with Bluetooth
Reboot your smartphone or restart your smartphone’s Bluetooth.
Failure to receive message / calls notifications
Message / call notification function works when the watch
connects to your smartphone via the app. Please kindly refer to
the following tips:
1. Go to your smartphone Settings, find the Letsfit app, enable
the Location and all Notifications.
2. Enable your phone’s Bluetooth and go to the Letsfit app to pair
the watch.
3. Open the app. Go to the "Device" page → "Notification Alerts",
turn on "Notification Alerts".
4. Make sure the "Do Not Disturb" function is not enabled on the
watch.
- 18 -
FAQs
- 19 -
The watch is disconnected from the Letsfit app on
your smartphone
The watch will disconnect from your smartphone in the
following cases:
1. Smartphone Bluetooth is off or exceeds the Bluetooth
connection range (the maximum Bluetooth connection range
is 10 meters and can easily be reduced by walls, furniture,
etc.)
2. The Letsfit app is closed on the phone. (This can occur
automatically under certain circumstances.)
To reconnect the watch to your smartphone, please kindly take
the following steps:
1. Restart the Bluetooth of your phone.
2. Clear all running / background processes on your smartphone
and restart the Letsfit app. Then the watch will reconnect to
your phone automatically.
Blood Oxygen Level Measurement Accuracy
The Blood oxygen level will be affected by factors such as
motion, watch placement on the wrist, skin temperature and
skin perfusion. These factors will cause fluctuations in blood
oxygen measurements.
For a single measurement on the watch, please wear the watch
a finger-width below the wrist bone, snug but comfortable on
your wrist. When measuring, stay still and make sure your wrist
is flat with the watch facing up. If you are sitting, you can rest
your arm on a table with the watch facing up.
The smart watch blood oxygen sensor isn’t a medical device
and won’t be able to diagnose or monitor any medical
conditions. If there is a problem with the measurement, we
recommend you consult your doctor.
- 20 -
We strive to build our products with the highest attention to
detail and craftsmanship. However, sometimes there are
occurrences of a defect, so we are happy to offer a ONE-year
hassle-free warranty on all our devices as we continue to
make amazing products. Please contact us if you have any
questions about our devices.
The device contains electrical equipment that may cause
injury if not used properly. For example, prolonged contact
may contribute to skin allergies for some users. To reduce
irritation, please read the safety guidelines on the following
pages to ensure proper use and care.
● Do not expose your device to liquid, moisture, humidity or
rain while charging; do not charge your device when it is
wet, as this may result in electrical shock and injury.
● Keep your device clean and dry. Do not use abrasive
cleaners to clean your device.
● Consult your doctor before use if you have any preexisting
conditions that might be affected by using this device.
● Do not wear it too tight. If your device feels hot or warm, or
if it causes any skin irritation or other discomforts, please
discontinue using your device and consult your doctor.
● Do not expose your watch to extremely high or low
temperatures.
● Do not leave your watch near open flames such as cooking
stoves, candles, or fireplaces.
● This product is NOT a toy – never allow children or pets to
play with this product. Always store the product out of the
reach of children. The devices themselves or the many
small parts they contain may cause choking if ingested.
Warranty
Important Safety Instructions
- 21 -
● Never try to abuse, crush, open, repair or disassemble this
device. Doing so will void the warranty and can result in a
safety hazard.
● If any parts of your product require replacement for any
reason, including normal wear and tear or breakage, please
contact us.
● Do not use your device in a sauna or steam room.
● Dispose of this device, the device’s battery and its package in
accordance with local regulations.
● Do not check any notifications, GPS, or any information on
your device’s display while driving or in other situations where
distractions could cause injury or hazard. Always be aware of
your surroundings while exercising.
Battery Warnings
A lithium-ion battery is used in this device. If these guidelines
are not followed, batteries may experience a shortened life span
or may cause fire, chemical burn, electrolyte leakage, and/or
injury.
● Do not disassemble, modify, remanufacture, puncture or
damage the device or batteries.
● Do not remove or attempt to remove the non-user-replace-
able battery.
● Do not expose the device or batteries to fire, explosion, or
other hazards.
Health Warnings
● If you have a pacemaker or other internal electronic device,
consult your physician before using a heart rate monitor.
● The optical wrist heart rate monitor emits green light and
flashes occasionally. Consult your physician if you have
epilepsy or are sensitive to flashing lights.
● Always consult your physician before beginning or modifying
any exercise program.
● The device, accessories, heart rate monitor, blood oxygen
level measurement and related data are intended to be used
only for general fitness and wellness purposes, not for
- 22 -
medical purposes, and are not intended to diagnose, monitor,
treat, cure, or prevent any disease or condition.
● The heart rate and blood oxygen level readings are for
reference only, and no responsibility is assumed for the
consequences of any false readings.
● While the optical wrist heart rate monitor technology typically
provides the best estimate of a user's heart rate, there are
inherent limitations with the technology that may cause some
of the heart rate readings to be inaccurate under certain
circumstances, including the user's physical characteristics,
fit of the device, and type and intensity of activity.
● The smart watch relies on sensors that track your
movements and other metrics. The data and information
provided by these devices are intended to be a close
estimation of your activity and metrics tracked, but may not
be completely accurate, including step, sleep, distance, heart
rate, and calorie data and blood oxygen levels.
● If you have eczema, allergies or asthma, you may be more
likely to experience skin irritation or allergies from a wearable
device.
● Whether you have the conditions above or not, if you start to
experience any discomfort or skin irritation on your wrist,
remove your device. If symptoms persist longer than 2-3 days
of not using your device, contact your doctor.
● If you sweat for more than two hours while wearing your
watch, be sure to clean and dry your band and your wrist to
avoid skin irritation.
● Prolonged rubbing and pressure may irritate the skin, so give
your wrist a break by removing the band for an hour after
extended wear.
- 23 -
Maintenance
● Regularly clean your wrist and the smart watch, especially
after sweating during exercise or being exposed to
substances such as soap or detergent which may adhere to
the internal side of the watch.
● Do not wash the watch with household cleanser. Please use
soapless detergent, rinse thoroughly and wipe with a soft
towel or napkin.
●While the watch is water resistant, wearing a wet band is not
good for your skin.
● If your bands get wet—for example after sweating or
showering—clean and dry them thoroughly before putting
them back on your wrist.
● Be sure your skin is dry before you put your bands back on.
● Do not bring your device into contact with any sharp objects,
as this could cause scratches and other damage.
● For light-colored arm bands, minimize direct contact with
dark-colored clothing, as color transfer can occur.
