TOA U-13R Unbalanced Line Input Module with Lo/Hi Cut Filters and Mute-Receive - Dual RCAUnbalanced Line Input with High Low Cut Filters and Mute Receive This is an input module for 900 series equipment. It accepts unbalanced line level signals from devices such as CD players, tape decks, and AM FM tuners. It has dual RCA jacks for device connection. It also has gain control, high and low cut pass filters, and responds to mute bus activation.