NuRezista Mainspring #581 for Waltham 0s Factory No. 2228 - Steel

NuRezista Mainspring #581 for Waltham 0s, Factory No. 2228, steel, new in envelope. See images for precise mainspring specifications. 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.