The Boss LS-2 Line Selector is a versatile and useful tool that can be used in a variety of different ways. It features two loops with separate volumes and multiple modes of operation: Loop A to Loop B. Loop A to bypass. Loop A to B to bypass. Loop A and B mixed to bypass Output select. The Boss LS-2 can be used as an amp or instrument selector, effect blender, or loop switcher. It can even power additional pedals when used in conjunction with a PCS-20A connection cord.