Comsco Mainspring #1120 for Hamilton 12/0s Factory No. 4128 - Steel

Comsco Mainspring #1120 for Hamilton 12/0s, Factory No. 4128, steel, new in envelope. See images for further details and 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