* One input and the Three position switch lets you select output 1, no output, or output 2. * Or, it can be used backwards to switch between two inputs to send to one output. * Hand built, good quality parts, rugged construction * Box measures 50mm x 35mm x 25mm (2"x 1.4"x 1"). Weights 23 grams. All jacks are 3.5mm (1/8") sized. Basically you can switch between two inputs going to one output, OR one input switched between two outputs. The middle position is a mute.Zap Electric