Replaces the rotating coupler with a fixed one - if you intend to mount you spool holder on the side of the printer, you might be printing the Side Filament Guide Arm for P1P instead
print both pieces, the Adapter Core needs to be printed with the minimum possible layer height for a smooth surface
insert the Adapter Core into one of the connectors and attach it to the other one, it should fit snug without much wiggle - if it is too small or too big, scale the model by a few percent
separate the 2 pieces again and put them into both ends of the Coupler
attach 2 PTFE-Tubes on either end and test, if the Filament slides through smoothly
if everything works, remove the pieces again, add a small amount of glue to the internal hex shape and insert the connectors again
install it onto your printer with the original screws