Inspired by SkinnyClip(TM) this is a different shape but works better for me. It is to make a strap a bit shorter in case you are skinnier than you used to be. Works for any strap (bra, jock, etc) that fits within the loop. To use, put a loop of strap into the loop part, and hook it over the straight part to hold it in. Pretty simple, I know

Printing:

I used PLA, at 0.2 mm setting, with brim, with it placed flat on the platform. You may need to re-orient it in your slicer.