NuTemper Mainspring #578 for Waltham 0s Factory No. 2220 - Steel

NuTemper Mainspring #578 for Waltham 0s movements, Factory No. 2220, steel, new in envelope. See images for precise mainspring specifications. I likely have several of these so the on 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 an adequate job of representing the item.