Marco Mainspring #402 for 18s Hamilton Factory No. 15 - Steel

Marco (C&E Marshall) Mainspring #402 for 18s Hamilton, Factory No. 15, steel, new in envelope. See image for further details. I likely have several of these so the one you get may differ slightly from the images. 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.