These are the hard to find Evinrude and Elto antique outboard motor piston rings.  These will fit 1941 to 1950 Speeditwin models # 6039. They are 2.75 by 3/32nds (093)   Standard bore.  We have 10 of these rings.  Price is each. Check your engine specs for the exact listing. These are butt end rings.  If your pistons has locating pins in the grooves you will have to file small notches in the butt end of the ring.  Look at the photos and email with questions.  Thanks for looking.