Newall SUPER Security Mainspring #626 for Hamilton 14/0s #5021 / 718440 - Alloy

Newall SUPER Security Mainspring #626 for Hamilton 22/0s movements, Factory No. 6221 / 718601, alloy, new in envelope. See images for precise 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.