The Warwick RockBoard Power Ace Mini Jack Converter is a power supply adapter cable designed specifically for effects pedals that require a 3.5mm male power jack. It features a flat and compact design with a 2.1 mm x 5.5 mm barrel connector (female) to 3.5 mm / 1/8" mini plug, and changes the polarity from negative center to positive center, allowing you to use "standard" power supplies and cables for your pedal.