Fitbit Flex 2
Tech specs 
SizeWidth: 11 mm
Small: 14 cm - 17 cm in circumference
Large: 16.5 cm - 20.6 cm in circumference
MaterialThe Fitbit Flex 2 wristband is made of a flexible, durable elastomer material similar to that used in many sports watches. Flex 2 also has a surgical-grade stainless steel clasp.
ChargingUSB. Charge time: One to two hours.
BatteryLithium-polymer
Battery lifeup to 5 days
Water-resistanceup to 50 metres (swim-proof) - 5 ATM
Weight36 grams
Sensor3-axis accelerometer, vibration motor
DisplayLED display with 5 indicator lights
Tap twice to see progress against your Main Goal
Screen size
ColorsBlack, Lavender, Magenta, Navy.
Other
Activity tracking 
StepsYes
DistanceYes
Calories burnedYes
ActivityYes
Floors
SleepYes
Heart rate
Vo2Max
Stress & recovery
UV exposure
Skin temperature
Galvanic skin response
Hydration level
Calorie intake
GPS
Running features
Swimming featuresSwimming can be auto-tracked with duration and laps of four strokes monitored: freestyle, breaststroke, backstroke and butterfly. The app shows the amount of time you've swam, distance, pace and impact on your day.
Other
Non-fitness functions 
Smartphone notificationsCall and text notifications
On-board music storage
Connected pay
Links 
Affiliate link*Amazon | Fitbit
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