Califone Deluxe Mono Headphone is ideal for maintaining classroom situations that features an adjustable polypropylene headband with rugged ABS plastic earcups and is able to reduce noise less than the ambient noise for added safety. 9 oz. Headphone includes a dynamic drivers with 600 ohm impedance, 6 ft. permanent coiled cord with 1/4 in. rugged monaural plug that is suitable with mono cassette players or recorders and a foam-filled replaceable ear cushions for added comfort.