Marco Mainspring #2937 for Gruen Veri-Thin V, 1½, 2½, 4 - Steel

Marco Mainspring No. 2937 for Gruen caliber V, 1½, 2½, 4 Veri-Thin and A. Michel caliber 520, 560 movements and perhaps other similar ébauche watches as well, steel, 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.