All of my rubber diver straps include the standard "fat boy" 2.5mm spring bars that are made for the larger diver watches. They have large holes in the lugs that accommodate these thicker bars, and these are the ones that come with the purchase of a rubber strap.
But some guys who love the Uncle Seiko straps want to wear them with a non-diver watch, or a diver watch that requires standard spring bars. These custom spring bars are the solution to that problem. Both 20mm and 22mm are collared for easier removal.
These are CUSTOM Spring bars with 2.5mm bodies and .8mm standard tips.