This is a single-barreled pen with a lot of metal in it. For a smaller pen (it takes a cross-type refill) it is a heavy pen. The bushings are the same size for both ends.
The CEO pen from Penn State Industries is the same pen as the Broker from Craft Supplies USA.
Tube Length(s)and Diameters
Dill letter size "U" - 0.368 inch
CEO Penn State Industries