Hamilton Factory Mainspring for 16s movements No. 318 / 718043 - Alloy

Hamilton Factory Mainspring for 16s 17 Jewel Movements, Factory No. 718043 (318), alloy, new in envelope. See images for further details. 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.