Comsco Mainspring #1165 for Illinois 6/0s Factory No. 47370 - Steel

Comsco Mainspring #1165 for Illinois 6/0s hunting movements, Factory No. 47370, steel, 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.