Charge HR syncs automatically and wirelessly to tablets, computers and 150+ leading iOS, Android and Windows smartphones using Bluetooth 4.0 wireless technology.Syncing to computers requires Internet connection and USB port. Syncing to mobile devices requires Bluetooth and Internet connection. Syncing range: 20 feetSyncs with Windows Vista and later, Mac OS X 10.6 and up, iPhone 4S and later, iPad 3 gen. and later, and leading Android and Windows devicesWe recommend charging your device every few days to ensure you are always tracking. Charge time: One to two hoursWater Resistance: Charge HR is sweat, rain and splash proof. However, the device is not swim proof or showerproof. With any wearable device, it's best for your skin if the band stays dry and clean. Battery life: lasts up to 5 days. Radio transceiver: Bluetooth 4.0