Comsco Mainspring #1119 for Hamilton 6/0s Factory No. 1721 / 1921 - Steel

Comsco Mainspring #1119 for Hamilton 6/0s 17j movements, Factory No. 1721 / 1921, steel, new in envelope. See images for further precise mainspring specifications. I likely have several of these so the one you get may differ slightly from the images. I specialize is hard to find watch parts so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do an adequate job of representing the item.