This special Flex cable stacks the voltages of two outlets of a CIOKS power supply and makes a series connection. The pedal will receive the sum of voltages of the two outlets used. This type 4 Stack Flex has a green 5.5/2.5mm center positive DC plug at the pedal end. Using two 12V outlets this Stack Flex should mainly be used to power older Electro-Harmonix pedals at 24V. You should preferably use two outlets with the same current rating. All the 24V pedals from Electro-Harmonix draw less than 100mA so using two 100mA outlets is just fine.