HR Mainspring A226 for Hamilton 18/0s Factory No. 2721 - Steel

HR Mainspring A226 for Hamilton 18/0s movements, Factory No. 2721, steel, new in dirty 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 an adequate job of representing the item.