Swartchild Black Shield Mainspring 44095 for Illinois 6/0s No. 47370 - Steel

Swartchild & Co Black Shield Mainspring No. 44095 for Illinois 6/0s movements, Factory No. 47370, steel, new in envelope. See images for further details. I likely have several of these so the one you get may differ slightly from the image. I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.