1In addition to the four Vol, Tone, Drive and Boost knobs, there are also two switches. The first has Comp Cut, FM and Vintage modes. These provide a range of usable tones, adding clean enhancement, tightening or maintaining neutral respectively. Two-way switch Mosfet and Standard produce smoother overload 2Comp Cut eliminate boundaries from the feedback loop. When you turn on the "Boost" knob, it will produce Monster Clean Boost tones and some rougher OD sounds 3FM stands for "midrange", which provides a more natural sound, and the tone improves transparency. Sounds great on Strat's Neck Pickup 4Vintage (old style) represents the deep tone of the old Fd2, throughout the entire mix 5MiniToggle 2, only when using the oldfashioned knob, mosfet and standard Toggle will work. MOSFET to control the volume 6If you use Standard function, the tone will be more asymmetrical, sweeter, and more open, and the sound will not be overwritten Item Type: Overdrive Pedal Material: Aluminum alloy shell Power Requirements: 9V DC center negative Current Consumption: 30mA Size: Approx. 11.9 x 9.4 x 3.8cm / 4.7 x 3.7 x 1.5in 1 x Overdrive Pedal 1 x Battery Cable 1 x Overdrive Pedal Footpad Customers need to purchase an external power supply by yourself to be powered on