Sennheiser's HD 200 PRO Headphones are a closed design offering isolation from background noise and neutral sound reproduction. They are designed primarily for studio applications but are also well suited to live sound monitoring. The noise reduction used is a passive type relying on physically blocking external sounds. This avoids the use of processing ( as employed in active noise reduction headphones ) which can reduce audio quality and would not be desirable for studio use. The other key design aim of the HD 200 PRO is comfort. Studio users often wear headphones for long periods of time so this model has been designed with a low tension headband and weighs just 184 grams. The cable is terminated in a 3.5mm mini-jack connector but a 6.3mm adapter is included for professional use. Their low impedance of just 32 ohms will mean that most devices can drive them loud so they are suitable for use with portable music players etc if required as well as with more powerful pro audio equipment. Finally one of the other main benefits of these headphones is their relatively low cost!