Comsco Mainspring #1210 for South Bend 12s Factory No. 55528 - Steel

Comsco Mainspring #1210 for South Bend 12s, Factory Number 55528, steel, new in envelope. See images for precise mainspring specifications. I likely have several of these so the one you get may different 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.