HR Mainspring A213 for 6/0 Hamilton No. 1721/ 1921 - Steel

HR Mainspring A213 for 6/0s Hamilton, Factory No. 1721 / 1921, T end, steel, new in envelope. See image for precise mainspring specifications. 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 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.