Nivaflex Mainspring for Gruen 215, 216 - Alloy

Nivaflex mainspring No 138½ for Gruen caliber 215 & 216 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.