Hamilton Factory Mainspring for 12s 17j Hamilton No. 718071 / 1228 / 3028 - Steel

Hamilton Factory Steel Mainspring for 12s 17 Jewel Movements, Factory No. 718071 / 1228 / 3028, 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 so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.