This elegant and light sensor gives you accurate heart rate on your Bluetooth Smart ready device. Bluetooth Smart technology provides wireless heart rate and low energy consumption so you can get more out of your training. The most accurate heart rate. Smaller sensor and soft strap ensures "second skin" comfort. Utilizes Bluetooth Smart to provide live heart rate on your device. Easy battery change with widespread CR2025 battery. Total operating time 300 hours. Compatible with latest Apple products: iPhone 4S and 5, iPod Touch (5th gen), iPod Nano (7th gen), iPad (3rd & 4th gen), iPad mini.