Fitbit Flex
Tech specs 
SizeSmall size fits wrists 14cm-16.5cm
Large size fits wrists 16.5cm-21cm
MaterialStainless steel casing, elastomer strap
ChargingUSB
BatteryLithium-polymer
Battery life5 days
Water-resistanceWater resistant up to 10 meters (1 ATM)
Weight10 grams
Sensor3-axis accelerometer, Vibration motor
DisplayFive white LED indicator lights
Screen sizeN/A
ColorsBlack, Slate, Tangerine, Teal, Navy, Violet, Blue, Lime, Pink, Red
Other
Activity tracking 
StepsYes
DistanceYes
CaloriesYes
ActivityYes
Floors
SleepYes
Heart rate
Vo2Max
Stress & recovery
UV exposure
Skin temperature
Galvanic skin response
GPS
Running features
Swimming features
Smartphone notifications
Other Auto sleep detection, silent wake alarm
Links 
View onAmazon | Best Buy | Target | eBay
Amazon US rating3.7 out of 5 stars
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