NuREZISTA Mainspring #722 for Hampden 12s Factory No. 6696 - Steel

NuREZISTA Mainspring #722 for Hampden 12s, Factory No. 6696, steel, new in possibly frail envelope. See images for further details. I likely have several of these so the one you get may differ sightly 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.