Star Mainspring for Hamilton 0s Factory No. 1535 - Steel

Star Resilient Mainspring for Hamilton 0s Movements, Factory No. 1535, steel, new in envelope. These were made by Waltham and sold under various names, including Star, and are pretty nice mainsprings. See images for further details. I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do an adequate job of representing the item.