NuVigor Mainspring #378 for 12s Hampden Factory No. 6696 - Steel

NuVigor Mainspring #378 for Hampden 12s Movements, Factory No. 6696, T end, steel, new in very frail envelope. See images for precise mainspring specifications. 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.