BOREL Mainspring SA310 for 12s Hampden Factory No. 6696 / 7696 - Alloy

BOREL Mainspring SA310 for Hampden 12s Movements, Factory No. 6696 / 7696, alloy, new in envelope. See images for precise mainspring 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.