Usage Tips:Features: 1.The product uses relay to switch signals, and the sound quality is not wasted. 2.It has no signal amplification function, just switching signal source. 3.It supports four channels of audio input and uses function switches can control the output of signals. 4.On the board of the function switch,there are four kinds of led lights, which correspond to different audio inputs. 5.The switching order of the audio signals is clockwise or counterclockwise. Descriptions: Color as shown Material: plastic + metal 1.This is a 4-way Relay Audio Input Signal Selector Switching RCA Audio Input Selection Board of Rotary switching for Amplifiers. Specifications: Model Number:WM-046 Power supply range: DC 7-30V AC 6-20V Noted:If choose DIY kit, need assemble to work,Please take full consideration to buy. Package Contents: 1 x Audio Input Signal Selector Switching Only 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.