Newall SUPER Security Mainspring #661 for 3/0s Hampden #9696 - Alloy

Newall SUPER Security Mainspring #661 for Hampden 3/0s Movements, Factory No. 9696, T end, 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 a pretty good job of representing the item.