Newall SUPER Security Mainspring #520 for Waltham 16s Factory No. 2218 - Alloy

Newall SUPER Security Mainspring #520 for 16s Waltham, Factory No. 2218, alloy, 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 so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.