Sandsteel Mainspring - South Bend 12s Factory No. 55528 - Steel

Sandsteel Mainspring for South Bend 12s, Factory Number 55528, steel, new in envelope. See images for precise mainspring specifications. These were available in a couple of different strengths and those that I can supply are found in the drop-down list. 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. Images do a pretty good job of representing the item.