Steel Mainspring for 18s Hampden Movements Factory No. 1696

Unmarked steel Mainspring for 18s Hampden Pocket Watch movements, Factory No. 1696, new in envelope. Could also very well fit in other 18s American watches too (hint, hint). 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 pretty good job of representing the item.