The Homebrew Full Metal Jacket is a simple yet effective distortion pedal that adds all the gain, sustain, and output you could want without affecting the tone of your guitar or amp. Even-order harmonics, JFET based construction, produces a distortion similar to overdriven preamp tubes. It features 3 knobs (Gain, Output, and Tone) and 2 footswitches (On/Off and Boost). The Boost footswitch increases the amount of distortion making the FMJ like a 2-channel tube amp.