Please read the profile before purchasing for a smooth transaction. This is a compact, high-performance ABY line selector (effector) that allows you to instantly switch channels with a single button. Despite its simple operation, it supports both "A/B switching" and "A+B simultaneous output," enabling a variety of sound creations. It can also be used as a simple switcher. Operates without power: The signal circuit is passively designed, so it can be used even without batteries or an adapter. (※DC9V power is only required to light the LED indicator). You can use it with confidence even on the go or in places where it's difficult to secure power. Bidirectional transmission: You can use the input and output bidirectionally, such as "splitting one guitar to two amplifiers" or "connecting two guitars to one amplifier and switching between them." Versatile modes: With a single toggle switch, you can select not only A/B switching but also "A+B mode," which outputs both A and B simultaneously. This expands the range of your performance. Durable construction: It uses a durable metal shell, ensuring a reliable design that can withstand hard use on stage. [Product Condition] Almost unused, only tested for operation. [Recommended Points] By using the "A+B mode," you can easily enjoy professional-like usage, such as creating powerful sounds by simultaneously playing two amplifiers. Because the basic functions can be used without connecting power, it's also ideal to keep in your bag as a spare in case of effector board trouble. It's compact and doesn't take up much space, making it a convenient unit that helps with board system construction.