HR Mainspring A307 for 16s Hampden Factory No. 3696 - Steel

HR Mainspring A307 for Hampden 16s 15 to 17 Jewel Movements, Factory No. 3696, T end, steel, new in envelope. See image for precise characteristics. 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 and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.