A very simple model to cap off the top of some gate posts.  For years i've been meaning to cap these to stop people putting rubbish in them.

Outer diameter of post 77mm, inner diameter 69.1mm

Would be best printed in something like PET-G, ABS or ASA.  Currently these are in PLA+, I've used PLA+ in cars and outdoors previously without issues but that will depend on your location / climate etc.