Elgin Factory Mainspring for 0s No. 1713 - Steel

Elgin factory mainspring Factory No. 1713 for 0s movements, steel, new in likely exceedingly frail envelope. Has the typical Elgin DB&H end, See image for precise characteristics. Elgin mainsprings are typically coated in very old grease and must be cleaned before use. I likely have quite a few of these so the one you get may vary slightly, or even significantly, from the images. I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.