Newall SUPER Security Mainspring #766 for 16s Illinois 60hr RR watch No. 47309 - Alloy

Newall SUPER Security Mainspring #766 for Illinois 16s Movements, Factory No. 47309, alloy, new in envelope. See image for precise characteristics. 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 so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.