NuREZISTA Mainspring #762 for 12s N.Y. Standard No. 4144 - Steel

NuREZISTA mainspring #762 for NY Standard 12s movements, Factory No. 4144, steel, new in envelope. See image for further details. 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 and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.