NuVigor Mainspring #519 for South Bend 16s No. No. 217528 - Steel

NuVigor Mainspring #519 for South Bend 16s movements, Factory No. 217528, steel, new in envelope. See image for further details and precise specifications. I may 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. Images do a pretty good job of representing the item