PM Mainspring for Felsa caliber 81 movements - Steel

PM ONYX steel mainspring for 6¾ ligne Felsa caliber 81 movements, and perhaps a couple of small Bulova movements as well, 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.