I can't find out what type this is beside the brand. It spins freely. It's two piece. I didn't see one like it when I searched. It seems to small for overall. Found at 1901 site if that helps the type of use.
Too funny, I didn't know Scovill made snaps either till I found one today!I’d say that’s a snap, not a button. Didn’t know scovil made those. Pretty cool