Comsco Mainspring #1235 for Rockford 18s Factory No. 644 - Steel

Comsco Mainspring #1235 for 18s Rockford, Factory No. 644, steel, new in possibly very frail envelope. See image for precise mainspring specifications. I likely have several of these so the one you get may differ slightly from the images. 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.