KBK Mainspring #3801 for Elgin 37s No. 4457 - Steel

KBK Mainspring #3801 for Elgin 37s Car Clock movements, Factory No. 4457, steel, new in envelope. See images for further details. Not very familiar with the supply house (would love to find them in a catalog) but they look like a really nice mainspring. 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 so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.