Motherboard and switch cable length 30CM with knobRelay-type 4-channel audio source selection, audio source switching, input selection board (actually 1-4 channels can be adjusted)The use of 1.6mm thick double-sided tin-plated PCB provides the most direct and fidelity switching of audio sources. The board is stereo dual-channel.The power supply voltage is a single group of AC12-15V. AC lotus seat hole distance is 13MMColour:As shownMaterial:PCBPackage Contents:1 x Audio source switch input selection boardOnly the above package content, other products are not included.Note: Light shooting 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.