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Features

Overview: The Koss QZ900 full-size headphones are equipped with battery-powered Active Noise Cancellation circuitry to shut out external noise, so all you hear is your music. The headphones comes with a detachable cord and a stylish zippered storage case.

Active Noise Cancellation: The QZ900's Active Noise Cancellation (ANC) is a special noise-canceling circuit that introduces sound waves from the outside, that are 180° out of phase with the incoming signals. The external noise is canceled out, so all you hear is your audio source. Low frequency sounds from airplanes, lawn mowers, and fans are dramatically reduced. With distracting noises eliminated, you can lower the volume of your electronics for better sound quality and less distortion. The ANC is powered by a single "AAA" battery (not included), which provides approximately 50 hours of active noise cancellation.

Detachable Cord: The headphones have a 4' detachable cable that plugs into the left earcup. It has an in-line volume control and 3.5mm plugs on each end. You can detach the cable and still enjoy passive or active noise cancellation.

Warranty: The RUK50s are covered by the Koss Stereophones Limited Lifetime Warranty.

Specifications:

• Frequency Response: 20Hz-20kHz
• Sensitivity (dB/1mW): 100dB
• Nominal Impedance: 32 ohms