Illinois Factory Mainspring No. 47350 for 12s movements - Steel

Illinois Factory Mainspring for 12s movements, Factory No. 47350, steel, new in frail envelope. One of the beautiful thing about factory mainsprings is that they pretty much always fit. See images for further details. I likely have several of these so the item may vary in differ slightly from what is shown in the images. See images for further details. 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.