Hamilton Factory Mainspring for 6/0s Hamilton No. 2521 - Steel

Hamilton Factory Mainspring for 6/0s Hamilton 17j Movements, Factory No. 2521, steel, new in possibly frail envelope. See image 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.