HR Mainspring SA311 for 12s Hampden Factory No. 12696 - Alloy

HR Mainspring SA311 for Hampden 12s movements, Factory No. 12696, T End, alloy, new in envelope. See images for precise specifications. 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 an adequate job of representing the item.