Fitbit BlazeFitbit Ionic
Tech specs 
SizeWidth 40mm
(Sizes depend on type of band)
Watch Width: 38mm
Watch Thickness: 12mm
MaterialStainless steel clasp, Classic band (elastomer), Metal band (stainless steel metal), Leather band (soft, genuine leather)- Strong & lightweight 6000 series aerospace-grade aluminum.
- The wristband is made of a flexible, durable elastomer material
ChargingUSBUSB
BatteryLithium-polymer
Lithium-polymer
Battery lifeup to 5 days4+ days with a GPS battery life up to 10 hours (1-2 hours charge time)
Water-resistanceSweat, rain and splash proof.up to 50 metres (swim-proof) - 5 ATM
Weight43 grams50 grams
Sensor3-axis accelerometer, 3-axis gyroscope, Optical heart rate monitor, Altimeter, Ambient light sensor and Vibration motorAltimeter, 3-axis accelerometers, digital compass, GPS, optical heart rate monitor, ambient light sensor, pulse Ox, vibration motor.
DisplayTouch-screen colour LCD.Hi-res touchscreen (up to 1000 nits). Corning Gorilla Glass 3 display.
Screen size19.05mm x 25.4mm29 x 21mm, 348 by 250 pixels
ColorsClassic (Black, Blue and Plum), Leather (Black, Camel and Mist Gray), MetalComes 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 
StepsYesYes
DistanceYesYes
Calories burnedYesYes
ActivityYesYes
FloorsYesYes
SleepYesYes (light, deep & REM)
Heart rate24/7Yes + HRV (premium subscription)
Stress & recovery
Pulse OxYes
Respiration rateYes (premium subscription)
UV exposure
Skin temperatureYes (premium subscription)
Galvanic skin response
Hydration level
Calorie intake
GPSConnected GPSGPS/GLONASS
Running featuresPace, distance & routes
Swimming featuresLap count, duration & calorie burn
Other Guided breathing, music control.- Guided breathing sessions
- Female health tracking
Non-fitness functions 
Smartphone notificationsYesCall, text and calendar notifications
On-board music storageYes, 2.5GB (300 songs) + access Pandora
Connected payYes
LTE
Links 
Affiliate link*Amazon | FitbitAmazon | Fitbit
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