The AB-1 is great for a musician needing quick access between two different amplifiers and/or two different instruments.
Each 1/4 inch unbalanced output channel (A or B) has its' own LED to indicate which channel(s) is/are on. Also, each output channel has its' own independent, rugged on/off foot switch. It has a paralleled 1/4 inch input/output jack for auxiliary use (tuner output). This product is built in a durable steel box and comes with a 9-volt battery to power the channels' LED lights. The unit will operate without the battery, but the lights will not function.