The Sennheiser HD202II are closed, dynamic hi-fi stereo headphones. Good insulation against ambient noise and a deep bass response make them the ideal companion for DJs - or anyone who likes to listen to modern, powerful music without disturbing others. High efficiency drivers for maximum performance. Sennheiser HD202II Closed Back Headphones Features include Closed,dynamic, semi-circumaural stereo headphones .Earcups can be removed from the headband ,Specially designed damping material ensures powerful bass response ,Lightweight turbine diaphragms for low bass .