NuVigor Mainspring #517 for South Bend 18s No. 29528 - Steel

NuVigor Mainspring #517 for South Bend 18s Movement, Factory No. 29528, T-end, steel, new in envelope. See images for further details and precise mainspring specifications. I may have several of these so the one you get may differ slightly from the images. Not an easy mainspring to find. 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