This split adapter Flex makes it possible to power two pedals using only one outlet of the power supply. You’ll need to attach two standard Flex cables to this adapter and in this way you can choose the lengths of the cable for the two pedals individually and also the type of plug needed for each of the two pedals.
If you’re looking for a simpler and cheaper way to power two pedals with a 5.5/2.1mm centre negative DC-plug standard (BOSS standard) using one outlet please have a look at CIOKS Split Flex (prod. no. 1035).