Sandsteel Mainspring for Illinois 0s & 3/0s Factory No. 47358 - Steel

Sandsteel Mainspring for Illinois 0s & 3/0s, Factory No. 47358, steel, new in envelope. See image for precise mainspring specifications. 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 and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.