Newall SUPER Mainspring #413 for 16s Elgin No. 817 - Alloy

Newall SUPER Security Mainspring #413 for Elgin 16s, Factory No. 817, 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.