Robusta Mainspring No. 1082 for Gruen caliber 405 - 406 - Steel

Robusta No. 1082 steel mainspring for Gruen calibers 405 - 406 movements and quite likely others as well, 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.