Newall Security Mainspring #611 for 16s Hamilton No. 318 - Steel

Newall Security Mainspring #611 for Hamilton 16s Movements, Factory No. 318, steel, new envelope. See images 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 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.