This is just a bolt, designed with a hole through the center, should be just the right size for 6.7 mm diameter double jacketed outdoor CAT 5E cable to go through, outer diameter should thread into a smooth 3/8" hole, printing in PET-G provides softer than metal threads, so they will grab the hole they're being twisted in to, but not deform the 3/8" hole. Heating the hole first should allow the threads to melt in & grab...

This wasn't intended to make sense unless your name is Andy, and you know me personally, and know what this part is about. Andy.