PERMA-LOY Unbreakable Mainspring for Gruen 405, 406 - Alloy

PERMA-LOY Unbreakable Mainspring for Gruen caliber 405, 406 movements and other Gruen calibers as well, alloy, new in envelope. See images for precise mainspring specifications. I likely have several of these so the one you get may differ very sightly 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.