Wireless Bluetooth 4.1 Technology with A2DP stereo music and pure, clear sound, ideal for high quality music while running, jogging, cycling, skating, etc Good noise isolation to create the optimal environment for listening to your favorite tunes, built-in microphone with noise cancellation for clear calling and friends chatting Sweat-proof, lightweight and ergonomic design to enhance your comfort; comes with interchangeable earbuds and ear hooks for secure and personal fit when walking or exercising Built-in rechargeable Lithium battery lasts up to 20 hours of talk/play time or 20 hours standby, universally compatible with most Bluetooth-enabled phones. Works with iPhone, iPad, Android and Windows Smartphones tablets and other Bluetooth devices.