HR Mainspring A126 - Elgin 15/0s No. 5550 - Steel

HR Mainspring A126 for 15/0s Elgin, Factory No. 5550 steel, new in envelope. See images for precise mainspring characteristics. 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.