HR Mainspring E538 for BFG caliber 688 - Steel

HR Ev-R-Last No. E538 steel mainspring for Baumgartner (BFG) caliber 688 movements plus perhaps similar ébauche watches, 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 an adequate job of representing the item.