Hamilton Factory 16s Mainspring Factory No. 317 - Steel

Hamilton Factory Mainspring for 16s 17-21 Jewel Movements, Factory No. 317, steel, new in envelope. See images for precise mainspring specifications. The beautiful think about factory mainsprings is that they always fit! 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 an adequate job of representing the item.