RCA L/R stereo audio switcher 4 IN 1 OUT or 1 IN 4 OUT. Main functions: (1) select audio input between 1/2/3/and 4 with knob siwtcher and get one output; (2) select audio output between 1/2/3/and 4 to receive one input Suitable for multiple sources signal select or multi-room paralleled amplifier or active speaker distribution of the same signal playback. Use audio rotary switch/Lossless device, easily switch between different audio in or out. Stereo Switch Box with Signal Lossless, Sturdy Aluminum case Strong Anti-Interference, Compact Connector Distributor RCA L/R Stereo Splitter Boxes. Plug and play, No power needed, 't affect sound quality. colour:Black Material:metal size:10.7 x 9.2 x 4.1cm Package Contents: 1 x Bi-Directional Audio Switcher Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.