RN Mainspring No. 319 for Gruen caliber 311, 355, AS 525, 557, 624, 962 - Steel

RN steel mainspring No. 319 for Gruen calibers 311, 330, 355 & AS calibers 525, 557, 624, 962 movements and perhaps 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.