Nivaflex Unbreakable Mainspring N2141 for Gruen 405, 406, 410, 411, 420, 421, 425, 426 - Alloy

Nivaflex Unbreakable Mainspring N 2141 for Gruen caliber 405, 406, 410, 411, 420, 421, 425, 426 plus perhaps other similar ébauche movements as well, alloy, 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.