Newall Security Mainspring #756 for 16s Illinois No. 47316 - Steel

Newall Security Mainspring No. 756 for Illinois 16s Movements, Factory No. 47316 or 573 depending on how old your catalog is, steel, new in frail envelope. See image for further details. 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.