Sennheiser HD 660S2

These headphones are incredible. They've been used 2-3 times in a professional studio environment and are essentially in mint condition. All original cables and adapters included with original drawstring carry bag. It is free of any performance issues, and has no scratches, blemishes, or other cosmetic flaws.

From the manufacturer:

From thundering timpani to the beat of electronic dance music, nothing creates drama like powerful bass, and with Sennheiser's non-fatiguing, high-end HD 660 S 2 headphones you can get even more impact and emotion. These headphone’s warm, relaxed tone is reflected by their outstanding comfort, timeless styling and elegant bronze accents. The open-back design also makes a pair of HD 660 S 2's great for long sessions. This updated model brings the same world-class precision and resolution as the HD 660 S, allowing you to pick out individual instruments and discover new sonic details.

Sennheiser's engineers explored every opportunity in their quest to improve on the lauded HD 660S design. They spent considerable effort optimizing airflow around the transducer and revising the surround, dropping the resonance frequency to 70Hz. The coil has also been revised for cleaner impulse response. Sensitivity over the entire frequency spectrum has increased, and sound pressure at the lowest octaves has doubled. Now you can really feel the music. With warm tuning, smooth treble and strong bass, the standard-setter for extended listening is now the standard setter for extended bass as well.