It is the result of several years of tweaking and improving the Marshal Bluesbreaker design, with 4 times more headroom, two times the available gain, and a more useful tone control. The Bright Cut toggle allows the perfect level of EQ for your rig. It is touch sensitive and dynamic thanks to the perfectly balanced frequencies and the tone knob reacts as a high frequency roll off. It cooperates with single pickups or humbuckers. It has enough clean headroom to be used as a boost. Only works with a standard 9V power supply (not included). The V4 version offers double the headroom and a Gain toggle which activates a new boost mode, more powerful and with more low-end. This switch can be remotely activated by way of the Remote Gain 1/4" jack on the right by plugging the optional Red Remote controller.