Parametric Cap / Plug with Optional Tether

Started out as a remix of someone's work, but so changed now as to irrelevant. Name says it all. I've only printed it in TPU, for which it works great, though I'm sure it would be ok in other materials too.

Attached STLs for a few variants based off of this:
* A Hi-Lift Jack Handle Cap, which has a couple retainer "nubs" added. Designed around the Baja Buster handle actually. That way when it smacks you in the face, it hurts less...
* Jack Shaft Cap is for the handle of my floor jack. Also