The RDL EZ-HK3 Audio/Video Hum Killer is a high-quality video transformer isolation module. It's designed specifically for use with unbalanced high-impedance audio inputs and 75-Ohm composite video. The device features both input and output connections on gold-plated RCA jacks. Each input jack is electrically isolated from the case itself as well as from the output ground. Each output jack is connected to the rear panel ground-lift switch, which is designed to eliminate hum due to ground loops. Ground loops are common when the EZ-HK3 is installed between a video source, such as a computer or DVD player, and the input of a grounded video monitor or projector in an AV or video system.