I don’t have tubing in the right size for any of my 5mm stones. This is a premade bezel that I soldered upside-down so I could grind a new seat, only to find I don’t have the right size bur, crap! I read on ganoksin about using a dapping punch to enlarge the bezel – DON’T DO IT! Talk about a round seat, I chipped this rather expensive natural zircon in the process of trying to set it, and sent two additional stones flying among the detritus of my studio. Despite annealing after all of this, the bezel is too hard for me to move by hand. I give up for tonight.