Radial Engineering Highline Mono - passive line isolator balances the signal to eliminate hum caused by ground loops; linear frequency response from 10 - 70,000 Hz; inputs: 2x 6.3mm jack (1x thru for looping through the input or 2nd input); output: 1x male XLR; switchable Gnd/Lift and SUM; 1:1 transmission with precision-wound Jensen transformer; no external power supply required; dimensions (WxDxH): 70 x 108 x 44 mm