Swartchild Black Shield Mainspring for Hamilton 18s No. 232 - Steel

Swartchild Black Shield Mainspring No. 4369½ for Hamilton 18s movements, Factory No. 232, steel, new in envelope. See images for further details. 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 unconditionally guaranteed. Images do a pretty good job of representing the item.