Ebtech Hum X Ground Line Voltage Filter Use only on equipment with current draw of 6 amps (720 watts) or less Not a ground lift - maintains equipment ground Suitable for use on 120V 60Hz grounded USA-style power outlets Use 1 Hum X per piece of gear. Multiple hum issues may require more than one Hum X. Not designed to get rid of cable related or guitar pickup related hum. NOTE: Check Instructional Video and User Manual before use