Pyle Bluetooth Fitness and Training Bicycle Sensors with Wireless Data Transmission for Measuring Speed, Cadence, RPM (PSBTC30) Bluetooth 4.0 Wireless Technology - Effectively Tracks and Records Heart Rate - Does Not Interfere With Sport Performance Download the App APA COACH+ free via App Store - Provides Instant Wireless Feedback and Data - Batteries 1 x Button Cell (Type: CR2032) Heart Beats Per Minute Wireless Transfer - Improves Workout and Monitors Your Health - Learn More and Make Training Fun Measures Your Heart Rate - Works for iOS Devices Only (iPhone 4S, iPhone 5, iPad, iPad mini) - Soft Fabric Strap for Comfort Also compatible with other training and fitness APPs on the market - Easily Wraps Around Your Chest Battery Required: 1 x Button Cell (Type: CR2032)