Newall SUPER Security Mainspring #531 for 12s Waltham No. 2224A - Alloy

Newall SUPER Security Mainspring #531 for 12s Waltham, Factory No. 2224A, 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 is hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.