ABY is applicable for instrument, amplifier, speaker(be sure to use speaker cable) and pedalboard. design of mode-choosing switch, which enable A, B channels transfer from respectively to simultaneously. In both two modes, ABY can be used in both positive and negative directions, signal can from A/B to C, or from C to A/B. ABY can work without supply (LED will not light ). Full metal shell, sturdy construction with good hand feeling. Very small and compact design takes little space on pedalboard. True bypass switch design minimizes tone loss.