These are bumpers to slide onto the bottom of worker nerf mags (only tested with 22's thus far)
These are designed to be printed in a soft filament to cushion the mags when they hit the ground, so you can gravity drop your mags with confidence for faster reloads.
As they are intended to be printed in a soft material they are intentionally very tight and likely will not fit if printed in a normal material (like PLA or ABS)
I personally use PolyMaker PolyFlex, so I can print even though my printer is not optimized for flexibles.
