Features: 100% brand new and high quality Connect to smart phone, computer or GPS watch using ANT+ & Bluetooth technology A sensor type heart rate monitor, it will detect and send your real-time heart rate to the smart phone accurately. Compatible for iPhone 4S and later, and for Android 4.3 or later. Supported apps: for Wahoo Fitness, for Strava, for MapMyRun, for Endomondo etc. With the chest strap based on high quality material, it can be attached to your skin closely. Ultra low power consumption, with a replaceable CR2032 battery. Specifications: Material: ABS Plastic Color: Black Battery: CR2032 Technology: Bluetooth 4.0(Low energy) Transmission: Wireless Bluetooth Transmitter size: Approx.6.7* 4cm(L*W) Belt size: Approx. 64-95cm * 3cm(L*W) Net Weight: 82g Note: Transmitter: Attach it to the strap in the right directions. Battery: Open and close it with a coin. Package includes: 1 * Transmitter Device 1 * Adjustable Elastic Strap