HR Mainspring A310 for 12s Hampden Factory No. 6696 - Steel

HR Mainspring A310 for Hampden 12s Movements, Factory No. 6696, T end, steel, new in envelope. See images for precise characteristics. Notice that someone has properly observed this is also usable in a ass Howard. 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.