KBK Mainspring #3808 for Elgin 18s No. 1956 - Steel

KBK Mainspring #3808 for Elgin 18s movements, Factory No. 1956, steel, new in envelope. See images for precise specifications. 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.