Benrus Factory Mainspring for caliber AZ - Steel

Benrus factory mainspring for caliber AZ movement, steel, new in sealed envelope. 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 and all watch parts are unconditionally guaranteed. If you need a part for a vintage watch I likely have it so feel free to inquire. Images do a pretty good job of representing the item.