Steel Mainspring for Rockford 6s #339 & Howard 12s #553 - Steel

Generic Steel Mainspring for Rockford 6s, #339, Howard 12s #553, Hampden 6s, #8696, and Illinois 4s #47354, new in replacement envelope. See image for further details. Usually I have some idea who made specific mainsprings but the mutilated envelope these originally came in didn't have a maker, just the information you see here, and honestly the use in the Illinois is probably a stretch. I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.