Features: New generation of Bluetooth 5.0: Lower power consumption, faster transmission speed than Bluetooth 4.2. The sound is almost zero-delay, has stronger anti-interference ability, and the signal is stable to meet your game needs. Two headphones are connected to one phone at the same time. Enjoy double-ear stereo HD sound. Semi-in-ear design, rounded curvature: Comfortable to wear Ultra-low power consumption, let the dual headphones fully listen to the song for 9 hours, put it into the charging box and automatically shut down and charge. The charging compartment can be used to provide a 24-hour listening experience as well as 3 power cycles. High-density grinding tools are adopted to manufacture high-density precision headphones. The materials are tightly combined and not afraid of water. In normal exercise, it is waterproof and sweat resistant. Specification: Product Name: HM51 Bluetooth Headset Bluetooth protocol: 5.0 Waterproof: IPX5 Bluetooth transmission distance: approx. 15 meters / 49.2 ft Headphone battery capacity: 4.0V / 50mAh Charging box charging time: 1.5h Single ear fully charged: 1.2h Music duration: about 16 hours Charging box capacity: 6.0V / 400mAh Standby time: 150 hours Charging interface: Micro-USB Net weight per earphone: approx. 3 grams Color: red, black (optional) Package List: 1* Pair of bluetooth headsets 1* Charging case 1* Data line 1* Instruction manual 2* Pair of ear caps 1* Woven bag 1、New generation of Bluetooth 5.0: Lower power consumption, faster transmission speed than Bluetooth 4.2. The sound is almost zero-delay, has stronger anti-interference ability, and the signal is stable to meet your game needs. 2、Two headphones are connected to one phone at the same time. Enjoy double-ear stereo HD sound. 3、Semi-in-ear design, rounded curvature: Comfortable to wear 4、Ultra-low power consumption, let the dual headphones fully listen to the song for 9 hours, put it into the charging box and automatically shut down and charge. The charging compartment can be used to provide a 24-hour listening experience as well as 3 po 5、High-density grinding tools are adopted to manufacture high-density precision headphones. The materials are tightly combined and not afraid of water. In normal exercise, it is waterproof and sweat resistant.