NuVigor Mainspring #303 for Illinois 16s Factory No. 47326 - Steel

NuVigor Mainspring #303 for Illinois 16s movements, Factory No. 47326, steel, new in 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 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.