Garmin Vivofit 4
Tech specs 
SizeWidth: 19 mm
Thickness: 9.4 mm
Circumference (small/medium): 122-188 mm
Circumference (large): 148-215 mm
Battery2 x SR43 user-replaceable
Battery lifeMore than 1 year
WeightRegular: 26 grams; X-large: 28 grams
Sensor3 axis-accelerometer
Display88 x 88 pixels
Screen size0.43" x 0.43" (11 x 11 mm)
ColorsBlack, White, Speckle
Other4 week internal memory
Activity tracking 
Calories burnedYes
SleepMonitors total sleep and periods of movement or restful sleep
Heart rate
Stress & recovery
Pulse Ox
Respiration rate
UV exposure
Skin temperature
Galvanic skin response
Hydration level
Calorie intake
Running featuresAccelerometer (calculates distance for indoor workouts, without need for a foot pod), personal records.
Swimming features
Other - Time/date, automatic daylight saving time, alarm clock, timer, stopwatch, Weather, Find My Phone
- Auto-goal, intensity minutes, True Up, Move IQ, Toe-to-Toe
Non-fitness functions 
Smartphone notificationsYes
On-board music storage
Connected pay
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