The Polar H7 is a combo heart rate sensor that provides live, accurate heart rate to your mobile training app, including Polar Beat, turning it into a smart training companion. The H7 also connects to many Polar products as well as compatible gym equipment. - Compatible with dozens of fitness apps - Compatible with iPhone 4S, iPhone 5, iPod touch (5th generation), iPad (3rd & 4th generation), iPad mini and iPod Nano (7th generation) - Transfers heart rate information while swimming with products which support 5kHz transmission