Features Easy Selection: 4 way amplifier button selection switch input, 2 sets of stereo speaker button selection switch output. and 2 sets of speakers can be independently turned on or off. Simple Operation: Multiple sets of stereo speakers can sound simultaneously, or one or multiple sets of speakers can be turned off separately, manually selecting the button switch. Strong in Power: The maximum power of each circuit is 300W. Signal input provides vacuum tube power amplifier signal no load protection function. Stable Signal: Manual selection of input and output switching, direct insertion and use, stable switching signal, and no additional dry switching or noise between channels. Easy Installation: Input output plug and play installation is convenient, and you can enjoy different audio experiences. The sturdy metal shell design is compact, easy to install, and the product does not require external power supply. Specification: Item Type: Passive Selector Switch Model: B042 Material: Aluminum Alloy Compatibility; Compatible with all types of power amplifiers and speakers. Connection: Input and output can connect heavy duty speaker wires or speaker pins through terminal ports. Power Amplifier Connection: Connect the power amplifier to amplifier 1, 2, 3, 4. Speaker Connection: Connect the speakers to positions A and B respectively. Power: Turn on your amplifier stereo device, this product does not require an external power supply. Input: Supports 4 sets of stereo inputs through banana plug. Output: Supports 2 sets of passive speaker outputs through banana plug. Power: Up to 300W Channel Power: Each channel supports up to 300W of power. Frequency Response: 10Hz-50KHz Output Impedance: 4-16 Ω Package List:1 x Passive Selector Switch 1 x User Manual Package List 1 x Passive Selector Switch 1 x User Manual