No need to buy a separate 18-volt power supply if you already have a Voodoo Labs Pedal Power multi-output power supply.
This Y cable combines two 9V outputs (both in standard 9V mode) from the Voodoo Labs Pedal Power power supply to create an 18V output. Great for powering pedals like the MXR Flanger and Dime Distortion, Crybaby 535Q, and various Fulltone and Keeley products. Also great for keeping your pedalboard power streamlined. Saves you both pedalboard space and money!