this product be initially release on 01\/01\/1984 and koss continue to produce the same pair of headphone more than 25 year later . if this be not a testimony in itself to the quality of the product , I do not know what be . I show off these thing to my friend who work in music -lrb- recording\/producing\/mastering -rrb- and be surround by thousand and thousand of dollar in sound equipment , and even they be thoroughly impressed . simply put , this product be a incredible product in itself , let alone for the price it be sell at .