NuVigor Mainspring No. 66 for Bulova caliber 10W - Steel

NuVigor No. 66 mainspring for Bulova caliber 10W and quite likely others. Steel, 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.