NuREZISTA Mainspring #557B for Waltham 16s 1945 Factory No. 2247 - Steel

NuREZISTA Mainspring #557B for Waltham 16s Model 1945, Factory No. 2247, steel, 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 and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.