Bulova Factory Mainspring for caliber 10BC - Steel

Bulova Factory mainspring for caliber 10BC, steel, new in sealed envelope. See image for further details. The wonderful thing about factory mainsprings is they always fit! That said the 10BC was based on the AS 1200. 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.