Sennheiser’s new HD 660S is the ideal open, dynamic headphone for the passionate audiophile. Meticulously crafted from hand selected components and specially developed acoustic materials, it delivers incredibly low harmonic distortion for an exceptionally natural, lifelike audio experience. With a lower impedance of 150 ohms, the HD 660S offers the versatility to enjoy reference class high fidelity sound with stationary and mobile players alike.