Description: Design: No power supply design, can be directly inserted and used, no input and output signal loss, switch transmission. Two adjustment methods: 1. by gain adjustment, 2. by frequency adjustment. Usage: mainly used to select common output devices and switch various stereo signal inputs. If there are two stereo signal sources (such as TV audio, MP3 player, CD player, video game, mobile phone, tablet, computer, recorder), the device needs to output to the power amplifier or active speakers. Stereo source switcher: Two sets of stereo source switchers solve the complicated line blocking operation. As long as the required input device signal source is uniformly connected to the switch, it can be easily selected. RCA interface: The input and output standard adopts RCA interface design, and the switch adopts accurate 2-position manual button switch. Specification: Type: auto power amplifier. Quantity: 1pc. Material: ABS + electric component. Color: black. Voltage: 12v. Frequency: 150Hz - 40Hz. Gain: 0db to -12db. Net weight: 70g/ 2.47oz. Package Includes: 1 Piece Auto Power Amplifier.