These are Evinrude and Johnson antique outboard motor piston rings. They will fit all the 14hp and15hp OMC outboards made from 1950 to 1956. OMC part number is # 301787 or # 378416.  That number # 378416 is for a set of three 301787 is for a single ring.   We have 6 of these rings. We sell them each.  If you need only one ring you don't have to buy a set.  2 3/8ths by 3/32nds.  Black iron.  Butt end.  Not pin cut.   Look at the photos and email with questions.  Thanks for looking.