Polar M400
Tech specs 
Size38 x 50 x 11.5 mm
MaterialSilicone, plastic
Chargingmicro USB
Battery190 mAh lithium polymer
Battery lifeup to 8 hours of training time with GPS and Bluetooth Smart heart rate sensor
Water-resistance30 metres
Weight57 grams
SensorAccelerometer, GPS
DisplayLCD, 128 x 128 px high resolution
Screen size23 x 24 mm
ColorsBlack, Pink, White, Blue, Red
OtherPLATFORM: Propriatory
MEMORY: 4 MB Flash memory
CONNECTIVITY: Bluetooth, Wifi
Activity tracking 
Calories burnedYes
Heart rateYes
Stress & recovery
Pulse Ox
Respiration rate
UV exposure
Skin temperature
Galvanic skin response
Hydration level
Calorie intake
Running featuresrunning cadence, recovery status, training benefit
Swimming features
Non-fitness functions 
Smartphone notificationsYes
On-board music storage
Connected pay
Affiliate link*Amazon
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