Bluetooth: 4.0 battery: 90ma polymer lithium ion battery charging time: 2 hours use time: about 7 days standby time: about 15 days waterproof: life waterproof compatible system: ios8.5 or above, android4.4 or above synchronization range: 3m (theoretical range is 10m, no interference) main functions: heart rate monitoring, step counting, calorie consumption, distance, rtc display, automatic sleep monitoring, call reminder, information push, alarm reminder, anti-lost, remote control, etc waterproof and dustproof: sweatproof, rainproof, splashproof display size: 0.96 inches screen type: tft connection parameters: bluetooth low energy bluetooth 4.0 synchronization other parameters: appearance material tpu product net weight: 22g product color: black, blue, red other functions: touch screen: full touch screen control method: push button switch data storage: record detailed exercise data for 7 days battery type: polymer lithium battery charging method: usb charging cable