Longines Factory Mainspring for caliber 4L - Steel

Longines Factory Mainspring caliber 4L plus perhaps similar ébauche watches, steel, new in open envelope. The wonderful thing about factory mainsprings is they always fit! These are often sold in sets of 3 (1/4 doz) but this is just a single mainspring. 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.