The BPC Compact Series MKII Tone Bender is a detailed replica of the 1966 PROFESSIONAL MK II although in a pedal board-friendly casing. The OC81D Loaded Professional MK II can be heard on many Jimmy/Led Zeppelin Tracks such as 'Whole lotta love'. Small casing variant Level and Attack controls 3x OC81D Transistors for smooth gain and lots of saturation Negative 9V Inlet As used by the Jimmy Page Limited production Please note all Compact Series Pedals require their own isolated 9V power supply. This is due to the nature of the PNP Transistors which cannot be used with a daisy chained supply.