IdiotBox Mad Doctor Stutter Effect Pedal The -RATE knob controls the speed rate of the ON/OFF switching adjustable from really really slow to super super fast, while the -RATIO control slews the amount of ON vs. OFF. With the -RATIO knob maxed there is less on and more off and gets rad and blippy. Back the -RATIO knob off and it results in more ON signal and less OFF. 4.7 x 3.7 x 1.18 enclosure, true bypass switching, common 9v center negative BOSS style power input and battery snap Power supply not included.