Features: 4 into 2 out/ 2 into 4 out passived amplifiers speaker Selector switcher: support 4ch input and 2ch output, 2ch input and 4ch output, to meet a variety of speaker selection needs. Sound Switching Distributor: It is convenient for users to flexibly switching the input source and output goal according to their needs, and realize the distribution and control of signal. Comparator: Ensure sound quality without loss, there will be no distortions and quality loss in process of signal transmission. Multiple switching options: suitable for different number of input and output combinations, to meet the user different needs. Simple operate: no external power, simplifying line setsup, easy and quick operate, suitable for variety of user scenario. Specifications: Color: Black Size: about 240x90x55mm/9.45x3.54x2.17inch Product model: B071 Channel power: Each channel supports up to 300W Output channel: Supports 2 pair of passived speaker outputs Switching: use 4-speed and 2-speed rotating mechanical silver dot switches for switching Frequency response: 10Hz-50KHz Output impedance: 4-16ohms Package Includes: 1x Amplifiers Speaker Switcher note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution.