Comsco Mainspring #1147 for Illinois 16s 60hr Factory No. 47309 - Steel

Comsco Mainspring #1147 for Illinois 16s 60hr RR movements, Factory No. 47309, steel, new in frail envelope. See images 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.