This comfortable GoHeart Heart Rate Monitor fits snugly and securely to almost any body type. With an easy-to-use comfort-made adjustable strap you can customize the GoHeart 100 to your personal preference. With standard ANT+ wireless connectivity your heartbeat band can connect to a host of devices with ANT+ support including GPS watches treadmills mobile phones and your favorite workout App's for accurate pulse monitoring and exercise strength control. Heartbeat Detection Range 30 to 240 BPM More than 300 hours of Transmission Time after Full Charge 5 meters Sensor Range 3.0 CR2032 Lithium battery.