Koss QZ-Pro Active Noise Cancellation Stereophone Delivers Combination Of Passive and Active Noise Reduction (Amr) Soft Vinyl, Closed Cushions Create A Seal Around The Ear Active Noise Reduction Circuitry Built Directly Into The Ear Cups Connectivity Technology: Wired Reduces harmful and annoying low frequency sounds in noisy environments Closed leatherette ear cushion for added passive noise reduction Dynamic stereophone element for extended frequency response (40-20,000Hz) Includes 2-prong airline adapter for in-flight use Collapsible design for portability. Turn the switch on to activate the ANC feature for noise cancellation