Model Number: 65G, Silver Plated Inner Diameter: 16.5mm Throat: I believe it's 4.62mm Shank: American Purchased about 16 years ago and stored for a long time. (This is not a LASKEY reissue.) The model number 65G is a rare model that is not currently available in the reissued versions and is not usually sold. The inner diameter is quite small, and those who usually use 17.00mm or larger will likely find it too small. If 17.00mm or larger feels tight, I hope you will consider this as an option. I have performed boiling sterilization and cleaning, but please understand the specifications and any deterioration (there are no dents, etc.) and purchase with no claims and no returns.