Moen AB BAR Loop Switcher ON/OFF via the BYPASS switch, and instantly switch between loops with the LOOP A/LOOP B switches. The TUNER/CLEAN switch also functions as a mute, so you don't have to worry about sound coming from your amp during tuning. In addition, each loop is equipped with an ON/OFF buffer circuit, allowing you to use them differently depending on the equipment connected to the loops. Manual and box included.