51 headset stereo pc headset usb headset design over ear type closed transmission mode cable types of connection usb 20 usb length of cable 3 m sound modes surround headset 51 hardware type of headphones headband features in line control volume control adjustable headband collapsible intergrated sound card function mute max power handling 500 mw headphone transmission range 20 20000 hz headphone impedance 32 ohm driver 50 mm number of dri