Elgin Factory Mainspring for 10s 1st Model KW Movements No. 823 - Steel

Elgin Factory mainspring Factory No. 823 for 10s 1st Model Keywind movements, Single Brace and Hole end, steel, new in envelope. See images for further information. This is a very uncommon mainspring to find so grab them while you can, but be aware the end as some early KW movements used this end and some used a Tab end (#2326). Elgin mainsprings are typically coated in very old grease and are often quite filthy so they must be well cleaned before use. I likely have several of these so the one you get may differ slightly 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.