Features:
Bluetooth heartrate belt, monitor your heart rate.
Bluetooth 4.0, wireless chest strap.
Ultra-soft elastic strap, comfortable fit.
Adjustable size, fits most people.
Snap attachment method, easy to use.
Support iPhone 4S, Android 4.3 or above.

Specifications:
Type: Wireless Heartrate Belt
Material: ABS 
Water Resistance: 30M Water-resistant
Bluetooth Version: Bluetooth 4.0
Support Device: iPhone 4S or above, Android 4.3 or above
Battery: CR2032 Battery (Included)
Battery Voltage: 3V
Chest Length: Approx. 98cm / 38.6in 
Chest Width: Approx. 3cm / 1.2in
Item Weight: Approx. 57g / 2oz
Package Size: Approx. 16.5 * 10 * 3.3cm / 6.5 * 3.9 * 1.3in 
Package Weight: Approx. 159g / 5.6oz

Package List:
1 * Heartrate Belt (Battery Included)