Samson Mainspring No. 3050 for Gruen 311, 330, 355, 400, 401, 500, 501, ETA 1000 - Steel

Samson No. 3050 steel mainspring for AS 525, 624, 962, Gruen 311, 330, 355, 400, 401, 500, 501, ETA 1000 caliber movements plus perhaps others, 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.