Bluetooth enabled wireless connectivity Built-in 4.0 Bluetooth connectivity gives you freedom from wires and up to 5 hours of your favorite soundtracks. It allows you to monitor volume and easily control tracks even while your smartphone remains safe in your gym bag – up to 40 feet away!Reflective cord design and retractable tetherMake the play for safety - the Reflect BT’s sweatproof cable provides high visibility in low light, perfect for night time runners.