NuTemper Mainspring #663 for 10s Howard No. 796 - Steel

NuTemper Mainspring #663 for Howard 10s movements, Factory No. 796, 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 an adequate job of representing the item.