Polar H7 Bluetooth Smart Heart Rate Sensor, Black Measures heart rate to provide ECG-accurate readings for tracking your workout progress Compatible with dozens of leading fitness apps, including Polar Beat Compatible with iPhone 4S and later, and with selected Android devices including Samsung Galaxy S3 and S4 using Android 4.3 or later Transfers heart rate information while swimming with products which support 5kHz transmission Included: Polar H7 Heart Rate Sensor, chest strap, and owner's manual