Buletooth V4.2High-Performance Wireless Stereo Chip, HB-900C V4.0 Wireless Neckband Stereo Music Sport Noise Cancelling Sweatproof(Black) The headphones is capable of having two devices connected to the phone at the same time and allows to automatically connecting after paired successfully to your Device for the first time. It saves more power, also guarantee HD stereo sound quality and provides you clear voice for calls. Ergonomic neckband design, you can wear the Headphone on your neck comfortably and perfectly, decrease the pressure of your ear, maximize the portability of listening Music on the go With powerful rechargeable battery, It can support up to more than 6hours music time, 7.5hours talking time, 120 hours standby time with a single charge, great for all day outdoor sports exercise and indoor entertainment. Secure fit for sports: neckband with wire clip design, you can wear yuppy for parkour, surfing, rock climbing, mountain biking, skateboarding continuous use