Luxury Products Level, World-Leading Digital Active Noise Cancelling (ANC): Professional ANC technology quells 92% low-frequency background noise of city traffic, office, plane cabin or hubbub.(Kindly note: Its NOT 100% sound cancellation, CANT quell human voice and dont need to start ANC in quiet environment.) It makes you focus on what you want to hear, enjoy your music, movies and videos. Noise cancellation function can work well both in wired and wireless mode 40Hours Playtime & Fast Charge: Built-in 750m AH energy-efficiency long-life battery provides up to 40H+ playtime to enjoy your own world without background noise, the 3.5mm audio cable as backup when in low battery. Advanced quick charge function, only 5-mins charge provides 2+ hours playtime,1-2hours charge to be full power. In addition, the over-voltage protection is designed especially for high-end cars, which make your charge faster and safer