Endurence Unbreakable-type Mainspring for Gruen 290, 291, 295 - Alloy

Endurence Unbreakable-type mainspring #83C for Gruen caliber 290 (and 291, 295) plus perhaps other similar ébauche movements as well, white 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 an adequate job of representing the item.