HR Mainspring SA226 for Hamilton 18/0s No. 2721 / 718501 - Alloy

HR Mainspring SA226 for Hamilton 18/0s movements, Factory No's 2721 / 718501, alloy, 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 in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.