Swartchild Black Shield Mainspring #4367 for Elgin 0s No. 1713 - Steel

Swartchild Black Shield Mainspring #4367 for Elgin 0s, Factory No. 1713 , Steel, new in frail envelope. See images for further details. This particular one is covered in major grease as most Elgin factory mainsprings are, and thus will need to be cleaned thoroughly before use. I likely have several of these so the one you get may differ slightly from the images. 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.