Marco Mainspring #512 for 14s & 16s Illinois Factory No. 47334 - Steel

Marco Mainspring #512 for 16s (end evidently also 14s) Illinois, Factory No. 47334, steel, new in envelope. I likely have several of these so the one you get may differ slightly from the images. I specialize is hard to find watch parts and all watch parts are unconditionally guaranteed. See image for precise characteristics. Images do a pretty good job of representing the item.