A Better Source 4 (or similar) Lens Dust Cap

Inspired by Jon Ares's Lens Cap, but redesigned from the ground up.

After printing a dozen of Jon's design, I realized the caps weren't staying on as well as I was hoping and they used a lot more material than necessary.  These caps use about half as much material, print in about half the time, and have a snug fit onto the tube.  

Printed at 0.28mm layer height on my P1S.  There are two files - one with a “regular” fit that is easy to remove but is unlikely to fall off on its own and one with a tighter fit.