The Runtastic Bluetooth Smart Combo Heart Rate Monitor uses the latest Bluetooth Smart technology to transfer your heart rate data to your Runtastic apps without an additional adaptor for your smartphone. In addition to tracking your speed, pace, altitude, distance, & duration, the data provided by this training equipment will make your workout statistics even more useful & reliable. The Heart Rate Monitor also has a 5.3 k Hz signal, which allows it to work with most cardio equipment in the gym (e.g. treadmill). * Compatible Runtastic Apps:* Runtastic PRO (i OS, Android)* Road Bike PRO (i OS, Android)* Mountain Bike PRO (i OS, Android)* Supported devices:*iPhone: iPhone 5s, iPhone 5c, iPhone 5, iPhone 4s* Android: Bluetooth Smart Ready devices running Android 4.3 & Samsung Galaxy S4* Weight: 89 g