This Bike Speed & Cadence sensor is specially designed for Bike cycling lovers. 

Features:
BT 4.0 TECHNOLOGY: This device is a BT smart device, widely compatible with smart devices with BT 4.0 or newer, for Android 4.3 or newer, for IOS 6.0 or newer. Speed / cadence / distance data can be shown on your mobile phone.
ACTIVE TRACKING: When you are riding, Cycling speed, cadence and distance data will be all shown on your smart device.
AUTOMATIC START: When you are riding, the device can auto transmit and sync to your smart phone and also it can be auto off when you are not riding, Save lot of energy. 
LOW-POWER: This item powered by 1 CR2032 cell battery and can last about 6 month.
COMPATIBLE APP: Compatible with the most popular cycling APPs on the market such as Wahoo Utility, MapMyFitness, MapMyRIDE, Wahoo Fitness, Biky Coach and so on.

Specification:
Technology: BT 4.0 
Material: ABS
Color: Black / White (Optional)
Battery model: 1 * CR2032 (included)
Battery Life: 300h
Transmission Range: < 3.0m /9.9ft
Sensor Size: 50 * 47 * 16mm / 2.0 * 1.8 * 0.7in
Net Weight: 25g / 0.89oz
Package size: 10.5 * 6 * 3.9mm / 3.2 * 2.4 * 1.6in
Package Weight: 52g / 1.84oz

Package List:
1 * Sensor
1 * Crank Magnet
1 * Wheel Magnet 
4 * Cable Ties
1 * Manual