Long accustomed to Koss Porta Pro use a helmet, I replace it there one week by one of those proposed here, thinking back the same features at lower cost ... of course ... the disappointment was enormous ... these helmets the summers have made with cheap parts chassis is made of a different material which makes the headset stand less on the head, from the first 5 minutes of use one of black sliding elements stands out, even the foam is different, and the sound is no exception ... of poor quality ... you can forget the impressive bass that made the charm of this helmet ... and to top all the volume was uneven from one ear to the other !! (Stronger left and right!)
In conclusion do not think getting a good deal here by finding an original Koss headphones at lower cost ...