HD 4.50 SE Wireless Bluetooth Noise Cancelling Headphones Black Sennheiser's HD 4.50 SE headset introduces high quality wireless sound for every day listening on the move. The closed back, around ear headset is the perfect companion for cable-free listening with mobile devices. Noise Gard: noise cancellation technology intelligently filters out ambient noise, while Bluetooth 4.0 and apt compatibility help deliver true Hi-Fi sound with a detailed acoustic performance. The headset is also designed for ease of use, with features such as NFC for hassle free pairing and intuitively positioned ear-cup mounted call and track controls. With a long-lasting battery life, robust high quality build and a compact foldable design for storage in the supplied protective case, the HD 4.50BTNC is perfect companion for an active lifestyle.