Features: Battery:110mah Charger time: 1-2 hours Standby time: if turn off bluetooth and heart rate, standby5 days, if turn on bluetooth and heart rate test,the battery just can use about 2-3 hours. Please use wall charger to charge it,not on computer. When you charge it, please clip the charger in right place. Heart rate: PPG,support heart rate test when having rest or sleeping. But Heart rate function will use much power.So when you sleep at night, you'd better turn off the heart rate function.You can test it when you rest. Top waterpoof reach IP67 Most-accurate heart rate monitor TPU material Touch button- easy view the data from screen call reminder with number display Display: 0.49 " Language: English and chinese Item size: 220*20*15mm weight: 30g Main CPU: Nordic Gravity Sensor: 3D sensor Display: OLED Button: touch button Bluetooth: 4.0V App Name: HPLUS WATCH IOS system: IOS 7.0 or above Android system: Android 4.3 or above vibration reminder: call remimder Heart rate monitor: green light laser Additional features: Time, Pedometer, calorie burning monitor, Distance, sport time, sleeping monitor Certifications & test reports: CE, ROHS Package Included: 1 x H3 Smart bracelet(Pack With Bubble Sponge) 1 x Charger 1 x User English Manual