In the HD 650, audiophiles will experience truly unique natural sound. With sound this good, long concerts in the comfort of your home are a certainty, so the HD 650 also sets standards in comfort and convenience. The HD 650 is a genuine masterpiece, which will satisfy even the most demanding listener. HD 650 – the Reference Class. | Sennheiser | | Refurbished Excellent | HD 650 | Hi-Res Audiophile Open Back Headphone | Quality Transducer and Diaphragm | Gray | Black | Best Buy