Elgin Factory Mainspring for 15/0s No. 5550 - Steel

Elgin Factory Mainspring for 15/0s movements, No. 5550 steel, new in envelope. See images for precise mainspring specifications. These came in several different strengths and those that I can supply are shown in the drop-down list. I have quite a number of these so the one you get may differ significantly from the images. Elgin mainsprings are typically coated in very old grease and must be cleaned before use. 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.