Elgin Factory Mainspring for 10s No. 5726 - Steel

Elgin Factory Mainspring for 10s movements, Factory No. 5726, steel, new in envelope. See images for further specifications. 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 guaranteed. Elgin mainsprings are typically coated in very old grease and this can look pretty filthy so they must be cleaned before use. Images do a pretty good job of representing the item.