Fitbit One
Tech specs 
Size48 mm x 19.3 mm x 9.65 mm (H x W x L)
MaterialThermoplastic. The clip is made of silicone and metal.
ChargingUSB
BatteryLithium-ion polymer
Battery life10-14 days / charge time: 1-2 hours
Water-resistanceSweat, rain and splash proof.
Weight8 grams
Sensor3-axis accelerometer, Altimeter, Vibration motor
DisplayOLED
Screen sizeN/A
ColorsBlack, Slate, Burgundy
Other
Activity tracking 
StepsYes
DistanceYes
CaloriesYes
ActivityYes
FloorsYes
SleepYes
Heart rate
Vo2Max
Stress & recovery
UV exposure
Skin temperature
Galvanic skin response
GPS
Running features
Swimming features
Smartphone notifications
Other Clock, silent wake alarm
Links 
View onAmazon | Best Buy | eBay
Amazon US rating4.3 out of 5 stars
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