Longines Factory Mainspring for caliber 8/37 - Steel

Longines Factory Mainspring for 8 ligne caliber 8.37 (8/37) plus perhaps similar ébauche watches, steel, new in open envelope. The wonderful thing about factory mainsprings is they always fit! 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.