Controls Rocktron products as well as other MIDI switchable products. 2 expression ports allow you to plug in Rocktron HEX expression/volume controllers. The ports have a smart function that recognizes the current status of both controller pedal ports upon the recall program change command being sent out. It has a power switch; Up, Down, and Recall controls; and an LED display that shows you the preset or controller assignment selection. Runs on a 9-volt battery, as well as external AC adapter or phantom power through select Rocktron processors and amplifiers.