Features: 1. V4.1 CSR Master 2. Support Bluetooth stereo music playback function (A2DP) 3. Can connect two mobile phones at the same time (one to two) 4. Display the battery on your iPhone 5. With noise reduction and echo suppression technology, the sound quality in any noisy environment is still excellent. 6. Long standby (about 7 days standby), up to 5 hours talking time 7. One-button power-on pairing, can remember to automatically connect