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

KBK Mainspring #3808 for Elgin 18s movements, Factory No. 1956, Single Brace (also called hook), steel, new in envelope. See images for precise mainspring specifications. Not very familiar with the supply house (would love to find them in a catalog) but they appear to be genuine factory 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.