USR Mainspring for Waltham 12s No. 2224A - Steel

USR Mainspring for Waltham 12s, Factory No. 2224A steel, new in very frail envelope. See images for further details. I may have several of these so the one you get may differ slightly from the images. I specialize is hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.