Swartchild Black Shield Mainspring #4360 for Elgin 12s No. 1712 - Steel

Swartchild Black Shield steel mainspring #4360 for Elgin 12s movements Factory No. 1712, new in envelope. See images for further information. I likely have several of these so the one you get may differ slightly from the images. I specialize in 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.