The AWEI AK3 Bluetooth Earphones use 6mm copper ring coils, strong rubidium boron magnets, and high-class carbon fiber diaphragms. It has deep low frequency, solid medium frequency, more abundant high-frequency details. Beautiful voice and music silkily fall in ears and keep in memories. Moreover, with its IPX4 waterproof performance, you are able to enjoy sports with a passion, no fear of sweat and rain!