With Built-in 40mm large-aperture drivers Bluetooth 5.0 technology providing solid bass and clear vocal. Enjoy the Hi-Fi sound like perform in front you losing yourself in the immersive music. BH21 Bluetooth headphone has come up with soft memory-protein earmuffs and a dedicated button for switching between Blaupunkt Music Mode and Bass Boost mode. Adjustable Headband with 180-degree swivelling provides a comfortable wearing experience. Perfect for your long-time music enjoying gaming or TV watching. It has 2-in-1 wireless and wired mode. Up to 24 hours playtime with a single charge in wireless mode or just slide the 3.5mm cable (included) to switch to wired mode which never powers off allowing you to bring your music everywhere. It has Latest Bluetooth version: 5.0 that provides a fast and stable connectivity with any Bluetooth enabled device Built-in Mic and button controls which makes it convenient for you to pick up any incoming call by simply pressing the button on the headphone.(Note: Mic volume control button and bass button work in wireless mode only). It has a dedicated bass boost button and is compatible with all phones smartphones with Bluetooth or 3.5mm audio jack such as all Android phones / iPhones and more. It comes with 1 year replacement warranty.