HR Nivastar Mainspring G211 for Gruen caliber 115, 405, 406, 410, 411, etc - Alloy

HR Nivastar Mainspring G211 for Gruen caliber 115, 405, 406, 410, 411, 420, 421, 426 plus perhaps more Gruens and similar ébauche watches, alloy, new in envelope. See images for precise mainspring specifications. I likely have several of these so the one you get may differ slightly from the images. 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.