The Whirlwind SEL A/B Instrument Switch Selector is designed to route one instrument/input to two outputs, OR two instrument/inputs to one output. The switching is achieved via dual mechanical push/push type switches. Its heavy-duty construction is virtually indestructible, perfect for demanding gigs. This foot switch box features professional 1/4" I/O jacks, A/B button, BOTH button, low-noise output, optical switching, and dual LEDs. Simply put, if you're a professional guitar hero or aim to be one, the Whirlwind SEL answers the call with affordability and versatility.