Newall Security Mainspring #537 for Waltham 6s & 8s Factory No. 2215 - Steel

Newall Security Mainspring #537 for Waltham 6s & 8s Model 1873 movements, Factory No. 2215, 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.