NuTemper Mainspring No.630 for 12s Hamilton 17-19j No. 1228 - Steel

NuTemper Mainspring No.630 for 12s Hamilton 17-19j, Factory No. 1228, steel, 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.