boAt Lunar Discovery w/ 1.39" (3.5 cm) HD Display, Turn-by-Turn Navigation, DIY Watch Face Studio, Bluetooth Calling, Emergency SOS, QR Tray, Smart WatchOperating System is androidSpecial Feature is DIY Watch Face, Daily Activity Tracker, Emergency SOS, GPS Navigation, Phone CallConnectivity Technology is BluetoothWireless Communication Standard isBluetoothBattery Cell Composition : Lithium Polymer