This is a snap-action clasp that locks onto a round rod.
This is meant to be a base object: you remix it (union) with something you want to attach to the rod (or attach the rod to). For example if you attach something to the rods on a 3D printer, or want to quick-release a rod (spool holder?) etc.
The design is parametric (open in Customizer or OpenSCAD) but for convenience a few pre-defined designs are included: 8, 10 and 12mm.
It prints in one piece without supports and requires no additional parts. The clasp is captive (it moves but doesn't fall off). https://youtu.be/-0oLQF7g45M
I started to design a dial indicator mount for Prusa Mk3 to help correct the bed warp, and needed a more elegant way to attach this to the round rods on X axis, to keep repeatability, make it easy to attach/remove, etc. The clasp mechanism turned out a project by itself, so I decided to publish this separately.