I won a toothbrush duofold from ebay, and I have both of the sac sizes specified on Richard Binder's site, but I dont know how to tell what size pen mine is. The pen measures about 5-5 1/16 in long and the barrell is about .5 in. in diameter. Any thoughts?
Edited by Mastersmith043, 26 December 2013 - 10:30 PM.