Wireless Bluetooth 4.1 Foldable Headsets, GRDE Retractable Headphones Neckband Style Sports Earphones Earbuds with Microphone, Compatible for Most Bluetooth Devices 1. Fashional foldable body (Easy to carry or put it on your bag) and retractable earbuds design, special neckband in-ear style keep the earbuds stable in ear when you are doing sports. CVC noise reduction, echo cancellation, sweatproof, enjoying music anytime anywhere 2. Bluetooth V4.1CSR8645HD stereo soundbuilt-in HD microphone, ensure Hi-Fi stereo music sound and strong signal, effective distance is about 10 meters/33ft ( Depend on environment, mobile phone and headset line distance) 3. Super long battery life: Charging about 3.5 hour, you can have at least 16 hours continuous music time, 18 hours talk time and 300 hours standby time; Also, the indicating LED light will on when you are matching the digital equipment or charging the headphones 4. Easy to operate: slide the ON/OFF button to turn the headphones on, no need to press and hold the MFB button for 5 seconds. With the voice prompt, volume up /downCH+/CH- control; Three different sizes of earbudmaking your wearing more comfortable 5. Never miss a call: Vibration for incoming call and broadcast phone numberyou can receive a call even you are listening to rock music