The HRB500 cardio armband is compatible with:Smartphones : Apple:Phones: iPhone 5 and later.iOS: 6 and aboveAndroid:Phones: with BLE technologyAndroid version 4.3 and above.Applications: (subject to variation according to the wishes of the editors)Decathlon Coach,Adidas Running by Runtastic,Strava GPS,RunKeeper,Nike + Run,etcFor your product to work with your phone, it is important that it is compatible with your phone, your operating system (OS) but also with your application. Today, most applications are compatible with Bluetooth Smart cardio products. However, it is advisable to check with the application provider.Product:First of all, you must verify that your watches/treadmills/others are ANT + or Bluetooth compatible. Some brands use bluetooth for cardio, others ANT +. Check with the manufacturer.Depending on the compatibility expressed by it, connect your HRB500 as a heart rate accessory.