Comsco Mainspring #1085 for Elgin 10/0, 16/0 & 18/0s Factory No. 1957 - Steel

Comsco Mainspring #1085 for Elgin 10/0s, 16/0s & 18/0s Movements, Factory No. 1957, steel, new in envelope. Distributed by Burton M. Reid and Sons. See images for precise mainspring specifications and 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.