Features: Bone Conduction Technology - Works by vibrations, sound transmits via cheekbone. And the open-ear design helps you stay alert to your surroundings. BT5.1 Technology - The latest BT5.1 technology bring faster wireless paring with your device, stable connection and transmission. Comfortable to Wear - Ergonomic design creates a more form-fit experience that wont slip or slide around during workouts. Sweatproof - IPX6 waterproof to resist light rain and sweat for sports. Quality Material - Titanium alloy enable the headphone lightweight, flexible but durable. Long Battery Life - Build in 150mAh lithium battery. Full charge take 2 hours, and play time around 8 hours. 3.