Nivaflex Unbreakable Mainspring N9104 for AS caliber 1221 - Alloy

Nivaflex Unbreakable Mainspring N 9101 suitable for AS caliber 1220, 1221 movements and perhaps others, alloy, new in envelope. See images for precise mainspring specifications. I likely have several of these so the one you get may differ slightly from the images. I specialize is 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.