1. No need for power supply design, direct plug and direct use, no loss of input and output signals, switching transmission, 2. This product is mainly used to select a common output device for switching various stereo signal input. If there are two stereo signal sources (such as TV audio, MP3 player, CD player, video game, mobile phone, tablet, computer, record player), the device needs to output to the power amplifier or active speaker. 3. Two sets of stereo source switchers solve the complex line plugging operation. As long as the required input device signal source is uniformly connected to the switcher, it can be easily selected. 4. RCA interface design is used for product input and output standards, and the switch is designed with manual push-button switch of precise 2 positions. Power supply: no power supply, plug in and use directly Frequency response: 20-20 kHz Distortion: Less than 0.002% Insertion loss: Less than 0.01dB Signal gain: 0dB SNR S/N: more than the 98dB Number of input channels: 2 stereo input signal sources Number of output channels: 1 channel stereo output Control switch: Accurate selection of gear 2, manual switch Net weight: 0.14kg/pcs colour:black material:metal size:69mm x43mm x39mm Package Contents: 2x Audio source signal selector