VOODOO LAB PPAY VOLTAGE DOUBLER ADAPTER 4". For pedals with higher voltage requirements, the Voltage Doubler Adapter will combine two 9V or 12V Pedal Power outputs to create a single 18V or 24V output. This adapter features two BLACK 2.1mm barrel plugs to a single BLACK 2.1mm jack for use with any standard power cable with a 2.1mm plug. Ideal for MXR Flanger and Dime Distortion, Crybaby 535Q, and various Fulltone and Keeley products. Features: Combines voltage of two Pedal Power isolated outs Compatible with all Voodoo Lab center-negative or center-positive DC power cables Custom-designed by Voodoo Lab for optimal performance with Pedal Power Nickel-plated barrel plugs secure solid connections between power supply and effects 22-gauge copper wire for superior current handling Coaxial design allows greater cable flexibility Durable PVC insulation ensures long cable life Part# PPAY