Swartchild Black Shield Mainspring #4352 for Elgin 18s No. 812 - Steel

Swartchild Black Shield Mainspring #4352 for 18s Elgin, 17j to 21j, Factory No. 812, 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 is hard to find watch parts so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do an adequate job of representing the item.