For pedals with higher voltage requirements, the reverse polarity 2.5mm Voltage Doubler Cable (PPEH24) will combine two 9V or 12V Pedal Power outputs to create a single 18V or 24V output. This cable features two BLACK 2.1mm barrel plugs to a single RED 2.5mm plug for use with center-positive polarity pedals. Ideal for Electro-Harmonix Deluxe Memory Man, Stereo Memory Man, Electric Mistress and others that require 24V. Flanger Hoax (18V) also requires this cable.