Jurgensen Mainspring #668 for 12/0 Hamilton Factory No. 4128 - Steel

Jurgensen Mainspring #668 for 12/0s Hamilton, Factory No. 4128, T end, steel, new in envelope. See images for precise mainspring specifications. I specialize in hard to find watch parts so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.