S-Logic Natural Surround Sound</br>Dynamic principle</br>Frequency range 10-22.000 Hz</br>Impedance 64 Ohm</br>Sound pressure level 102 dB</br>S-Logic(TM) Natural Surround Sound for a more natural?? lifelike sound</br>Safer listening?? less fatigue - SPL levels to the ear drum are decreased by up to 40% (3-4dB) for the same perceived loudness</br>ULE technology with MU Metal shielding to reduce radiation by up to 98% as compared to ordinary headphones</br>50mm professional durable Mylar driver provides high volumes and superb isolation</br>Zippered hard case?? extra ear pads and cables and demo CD included</br><br/>http://www.amazon.com/gp/product/B000YDYEDW