Samson Mainspring No. 5076 for Benrus R, Buren 410, 470, Eterna caliber 520 - Steel

Samson No. 5076 steel mainspring for Benrus caliber R, Buren caliber 410, 470, Eterna caliber 520, plus A.S. caliber 558 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.