With Bluetooth® Smart super low energy technology iOS device : iPhone 4S or above and devices with iOS 8 or above with BLE 4.0Android OS device : Smartphones with BLE 4.0 and Android OS 4.4 or above Advanced Bluetooth® Smart (BLE 4.0) super low energy consumption wireless speed & cadence dual sensor provides real-time ride information on your mobile training Apps and turns your smartphone into a personal training device.* iPhone is a registered trademark of Apple Inc.* Bluetooth® is a registered trademark of Bluetooth SIG, Inc. BATTERY: CR2032 x 1 (Included) BATTERY LIFETIME: (Approx) 900 hr MOUNT: Chainstay SIZE: 5.4 x 3.3 x 1.2 cm / 2.1” x 1.3” x 0.5” TECH: Bluetooth® Smart super low energy technology TRANSMISSION RANGE: < 5 meter (16.4 ft) WEIGHT: 21 g / 0.74 oz WATERPROOF: IPX 5