Rhythmmage Strapless Sports Heart Rate Monitor for Android and iPhone SUPPORT BLE 4.0& ANT+- RM uses the industry standard Bluetooth to ensure reliable, clear communication with smart phones and tablets, and move data seamlessly to 3rd party fitness applications STRAPLESS HR MonitorNo more uncomfortable straps to put on and take off, Or wrist worn devices that are so tight. ACCURATE IS THE KING-RM is applied to your chest or side where the super sensitive single lead ECG sensor captures a clear signal. COMPORTBLE 24-7-RM is a Band-Aid size tracker which is less than 10g. Our long-lasting adhesive pads can stay up to 30 hours without even thinking about the RM. BIOLOGICAL RECOGNITIONWhen you wear RM on the body, you can focus on your fitness and let the RM track your bio-signals and activity.