I don't know if all the Regina pipes have this feature but the sweet little cutty I got has a novel, to me, shank/stem interface. There is a narrow stainless tube pressed firmly into the shank. The tube is long enough to nicely fit into a narrow bore on the stem. Both the shank and the stem ends are flat faced. Thus at one shot this arrangement strengthens both the shank and stem with no downside that I can detect. Both the shank and the stem are much thicker and more robust than they would be with a conventional setup. It seems an elegant solution for a small pipe with a shank only slightly more than a quarter of an inch in diameter.