Backpacks features: H6 Smart Sensor ANT Bluetooth V4.0 Heart Rate Monitor For Mobile Cell Phone Color: we send based on the color or size of the main image of the product page. Quantity：we send based on quantity on title, if there is no quantity in the title, we send based on description. 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. Product Properties: Brand Name: none Power Supply: Battery Mounting Placement: handlebar Certification: CE Position of bicycle light: bike handlebar light Direction of bike light: Front bike light Light type: LED Material: Aluminum Alloy 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 1 * User Manual