A clip to keep 1.75 mm filament from unraveling off the spool.
I know, there's a bunch of these on Thingiverse, I tried a few but felt I could do better. So here it is... Yet Another Filament Clip.
It's small and quick to print
Lays flat on the spool, doesn't stick out
Zigzaggy channel is easy to load but grips the filament