Bulova Factory Mainspring for caliber 10BNCH - Alloy

Bulova Factory Mainspring for caliber 10BNCH and perhaps others, alloy, new in sealed package. The wonderful thing about factory mainsprings is they always fit. I likely have several of these so the one you get may differ slightly from the images. 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 an adequate job of representing the item.