Based around the desirable JRC4558 chip and 1990's Full-Drive circuit, with 2 toggle switches for many more sonic options, it is 30% smaller than the FD2-MOS and 15% smaller than the FD3 at only 11,3cm wide x 10,2cm deep. The left On/Of footswitch uses True-Bypass switching with exclusive Fulltone No-Pop" circuit. The right "Channel select" footswitch switches between Overdrive 1 or Overdrive 2, each with individually adjustable Volume and Drive knobs. 2 toggle switches to access the many clipping options. Left switch has Comp-Cut to removes clipping diodes, not a clean boost because it can distort the opamp, Flat Mids, a late 1990's Fulltone invention that feeds signal back on to the clipping diodes removing the Mid-hump, Vintage, a traditional 90's Full-Drive slightly asymmetrical clipping. The right switch has Wide which combines Mosfets &Schottky Diodes for more clarity, less compression, a more D*mble-like sound, Standard, traditional 90's FD2 slightly asymmetrical, Half-Clipped, another Fulltone exclusive, only clips the top waveform for extreme clarity, feel, and touch like you've never experienced!"