Handmade models with flush brass rings and brass inserts, length varies based on what I can get out of the material, is just 140mm long and made from 14 parts. The diameter is ~15.3mm. Made without CA glues, joined with threading, and finished only with Renaissance Wax.

The rings pattern of this model is in millimeter, from cap to barrel about, 3 - 1/5/1 - 3.
This is a turn cap model.

I call them desk pens because of the absence of a clip, and the cap does not go on the post.