Newall Security Mainspring #466 for Elgin for 18/0s No. 1957 - Steel

Newall Security Mainspring No. 466 for Elgin for 18/0s movements, Factory No. 1957, steel, new in envelope. See images for precise mainspring specifications. 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 guaranteed. Images do a pretty good job of representing the item.