Newall SUPER Security Mainspring #756 for 16s Illinois No. 47317 - Alloy

Newall SUPER Security Mainspring No. 756 for Illinois 16s Movements, Factory No. 47317, alloy, new in envelope. See image for precise mainspring specifications. 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.