VOCOPRO UG-9  U-series wireless Guitar System Plugs Securely Into 90 Degree Guitar Plug. Diversity Receiver Design Reduces Dropouts Caused by. Multipathing and Interference 16 Operating Channels Allow for Multiple Sets to be Used. Simultaneously Operating Range of up to 150 Feet. Adjustable Squelch Control to Minimize Outside Interference. Receiver Can Operate on 2 AA Batteries or DC Power Adapter