Swartchild Black Shield Mainspring for Waltham 16s Factory No. 2218 - Steel

Swartchild Black Shield Mainspring No. 4330 for 16s Waltham, Factory No. 2218, steel, new in frail envelope. See images for further details. 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 an adequate job of representing the item.