Darkglass Microtubes B3K Bass Overdrive Pedal with warm, clear, and punchy tube-like overdrives. Level: Controls the level of the Overdriven Signal. Blend: Allows mix of clean signal with overdriven. Drive: Sets the amount of preamp gain. Grunt Switch: Choose between 3 different Bass boost levels before the gain stages. Attack Switch: Features the same as "Ultra Hi" option in most tube bass amps, boost setting gives more clarity, presence and definition, off option will round up the sound, making it warmer and less sharp. True bypass relay, hybrid JFET and CMOS gain stages for a natural dynamic response, power by 9V DC power supply (not included - optional 108096), Made in Finnland