Hear the World, Heard Yourself : With a 40mm premium stereo driver unit , AOMAIS VOICE bring you the best music experience: rich and strong bass, crisp and clear highs. And AOMAIS bluetooth headphone is passive noise reduction technology instead of active noise reduction (ANC). Although the physical noise reduction method cannot completely isolate the noise, it can better enhance the sound quality and battery playback time. Soft and Comfortable Portable Design : Soft ear pads are wrapped in protein leather that simulates the texture of human skin and is soft and comfortable when worn. Stainless steel slider retractable design allows you to find the most comfortable position to wear ear but also increased its durability. It closed design allows you to better immersed in your own world. Wireless and Wired Your Music is Always On The Road: For Bluetooth CSR Latest technology, this item provides fast and reliable connection to Bluetooth devices such as cell phones, tablets, PCs, TVs and more within 33 feet. Wireless mode gives you up to 10 hours of play time. The Wired mode can be used as a wired headphone with the provided 3.5mm cable, which makes your headset never be powered off.