Newall SUPER Security Mainspring #653 for 16s Hampden No. 3696 - Alloy

Newall SUPER Security Mainspring No. 653 for Hampden 16s Movements, Factory No. 3696, 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.