PM Mainspring for Tavannes caliber 052 - ONYX Steel

PM ONYX steel mainspring No. 40 for Tavannes 5¼ ligne caliber 052 movements and quite likely others, 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.