This bundle includes 2 pack Voodoo Lab Cable Current Doubler Adapter - Two 2.1mm Straight Barrels - 2.1mm Female 4".For pedals with higher power requirements, use this current doubling adapter with a 2.1mm jack to combine two Pedal Power outputs. (Frequently used to combine outputs 5 & 6 on a Pedal Power 2+ to create a single 9V 500mA output.) This adapter will accept any cable with a 2.1mm plug.Power Supply Connector: 2.1mm Straight Barrel Plug (2)Pedal Connector: Jack for 2.1mm PlugPolarity: Standard (Center Negative)Length: 4 in / 10 cm