Progress Mainspring for 16s Hampden Factory No. 3696 - Steel

Progress Mainspring for Hampden 16s movements, Factory No. 3696, steel, new in envelope. See images for further details. Progress mainsprings were economy mainsprings so their finish is not always as fantastic as others but they're still good mainsprings. 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 suitable job of representing the item.