SPORTS BLUETOOTH HEADSET: one-button intelligent power on , IOS system with power display and power prompt, two-in-one function, can connect two Bluetooth devices at the same time. Voice dialing function, support for call clearing, terminal redial, call rejection. CSR4.1 Bluetooth chip, built-in sound adjustment, incoming vibration chime CVC broadband noise reduction. RETRACTABLE EARBUDS: automatic retractable headset, retractable cable can be pulled to the length you want, press the retractable button to automatically store the earbud cable. Never worry about tangling or cluttering again. Retractable headset with foldable design, easy to use and storage, protect the Bluetooth headset from damage and loss. SX-991 STEREO HEADSET: ergonomic, flexible and wear-resistant neckband and sweat-proof design allows you to wear the headset more comfortably around your neck and reduce the pressure on your ears. ULTRA-LONG STANDBY: This Bluetooth headset has a powerful 120mAh battery with up to 18 hours of continuous talk time, 16 hours of music time, over 300 hours of standby time, and takes less than 3.5 hours to fully charge. The button retractable, you can pull the earbuds and hang them around your neck when listening to songs. The earbuds can be pulled out at any time during use, and vibrate and report the number when a call comes in.