Infatigable Mainspring for ETA 2340, 2355, FEF 370, PES 220 - Alloy

Infatigable Permanent Power white alloy mainspring #551 for ETA 2340, 2355, Fleurier 370, Peseux 220 caliber movements plus perhaps others,  new in envelope. See images for precise mainspring specifications. I specialize is 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.