The ABY is applicable for the instrument, amplifier, speaker(be sure to use speaker cable) and pedalboard. The design of mode-choosing switch, which enable A, B channels transfer from respectively to simultaneously. In both the two modes, ABY can be used in both positive and negative directions, the signal path can flow from A/B to C, or from C to A/B. ABY can work without power supply (LED will not light up). Full metal shell, sturdy construction with good hand feeling. Very small and compact design takes up little space on the pedalboard. True bypass switch design minimizes tone loss. A/ Jack: Standard 1/4Inch Jack-MONO/ Power Supply 1: DC9V equal 300mA Power Supply 2: USB5V equal 300mA Item Size:90x48.5x42mm/3.54x1.91x1.65in Item Weight:178g/6.29oz Colour:Black Material:Aluminum Alloy Package Contents: 1 * ABY Channel Switch Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.