Fitbit Ionic
Tech specs 
SizeWatch Width: 38mm
Watch Thickness: 12mm
Material- Strong & lightweight 6000 series aerospace-grade aluminum.
- The wristband is made of a flexible, durable elastomer material
ChargingUSB
BatteryLithium-polymer
Battery life4+ days with a GPS battery life up to 10 hours (1-2 hours charge time)
Water-resistance5 ATM
Weight50 grams
SensorAltimeter, 3-axis accelerometers, digital compass, GPS, optical heart rate monitor, ambient light sensor, sensors & components, vibration motor.
DisplayHi-res touchscreen (up to 1000 nits). Corning Gorilla Glass 3 display.
Screen size29 x 21mm, 348 by 250 pixels
ColorsComes is Sport, Leather and Classic versions.
Other- Saves 7 days of detailed motion data – minute by minute.
- Saves daily totals for past 30 days
Activity tracking 
StepsYes
DistanceYes
CaloriesYes
ActivityYes
FloorsYes
SleepYes (light, deep & REM)
Heart rateYes (Stores heart rate data at 1 second intervals during exercise tracking and at 5 second intervals all other times)
Vo2MaxYes
Stress & recovery
UV exposure
Skin temperature
Galvanic skin response
GPSGPS/GLONASS
Running featuresPace, distance & routes
Swimming featuresLap count, duration & calorie burn
Smartphone notificationsCall, text and calendar notifications
Other - SpO2 sensor that measures blood oxygen levels
- Guided breathing sessions
- Store & play 300+ songs, plus access Pandora, no phone needed
- Built-in NFC chip stores credit cards for use on your watch
Links 
View onAmazon
Amazon US rating
Read moreReview