NuVigor Mainspring #304 for Illinois 16s Factory No. 47327 - Steel

NuVigor Mainspring #304 for Illinois 16s, Factory No. 47327, steel, new in distressed envelope. See images for precise mainspring specifications. 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 suitable of representing the item.