Headphone button switches the 1/4 output into headphone mode 1/4-inch 4.7megOhm input to deliver the full sound of piezos Input Pad for active basses XLR output with ground connect 1/4-inch low impedance output Rugged, all-metal housing Metal footswitches and jacks Silent-switching, custom footswitch actuators Utilizes included 9V, 200mA DC power supply.