Sennheiser HD 25 ALUMINIUM DJ Headphones Superb sound quality featuring tight bass, smooth midrange and detailed treble. Capable of delivering very high sound pressure levels (120 dB). Closed back, on ear design provides high attenuation of background noise with no sound leakage. (Contact pressure approximately 3.2N). High-grade machined aluminum ear cups help deliver both exceptional sound quality (&gt; .3% THD) and durability. Rotatable ear cup provides one-ear monitoring. Lightweight yet extremely robust construction provides both wearing comfort and durability. 70-ohm impedance is a perfect match to home and studio monitoring audio equipment. 2 year warranty.