Sanag Z51 is an innovative air-bone conduction Bluetooth headphone with an ergonomic back arc pod design for a stable and comfortable fit. Our open-ear design with a futuristic style allows you to be fully aware of your surroundings and free from ear buds. Overall it's light and airy, stable and comfortable. A single pair of headphones weighs just 12g with 360° uniform force. Touch controls and ear hooks combine ergonomics and SF-EARS fit technology to give users a comfortable wearing experience.