National Unbreakable Mainspring for Hamilton 6/0s No. 2321 / 2521 - Alloy

National Mainspring for 6/0s Hamilton, Factory No. 2321 / 2521 / 718201 / 718202, white alloy, 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.