Hamilton 18s Mainspring Factory No. 14 - Steel

Hamilton Mainspring for 18s, Factory No. 14, marked with the maker CYY on the actual spring, see images for precise mainspring specifications and further details. Evidently the CYY P/N was 52 and although I'm not familiar with the maker, it's a nice quality mainspring. I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do an adequate but perhaps somewhat incomplete job of representing the item.