A small mitten hook carabiner, handy for non-critical outdoor applications like hanging/attaching small gear items, securing tarps, hammock underquilts etc. Easily snaps in and out of cordage loops juts by pulling the cord through the hook opening, no need to unlatch the gate or anything. I use 95% scale for paracord and similar diameter cordage. Print in PETG (necessary for flexibility), flat on its side.

I use it as a part of my hammock setup, have a look at my other 3D printed hammock/outdoors accessories:

Guyline cord tensioner hook https://www.thingiverse.com/thing:4585765

Beefy Tri-Lobe Tent Stake Cap https://www.thingiverse.com/thing:4510042