This is a BIG MUFF type effector called "Large Beaver." It has a switch for a mid-scoop sound, and a tone bypass, making it easy to use with a wide range of sounds. The sound it produces is a roaring fuzz, and it's easy to incorporate into a pedalboard, making it a great choice. I previously acquired this excellent effector, but I'm selling it because I no longer use it and am decluttering.