The Sennheiser HD 205 is a set of medium-sized dynamic, supra-aural headphones designed especially for the dj on a budget. One-ear listening is crucial for the dj so the earcups are rotatable. Supra-aural means the headphones rest on top of the ear but don't surround them, still creating a seal with the ear to keep sound in and ambient noise out. This is important for mixing in noisy environments like clubs or parties. A protective pouch is included for travel and storage, and the cable is one-sided, only connecting to one side to power both speakers. The step up from these headphones are the HD 215 which offer greater Frequency Response as well as lower Total Harmonic Distortion(THD) which translates to a clearer, deeper sound with less overall distortion. The model below these are the HD 201 which offer as you would guess, lower Frequency Response and higher THD, and do not have rotating dj-styled earcups.