Sandsteel Mainspring for Elgin 12s No. 1720 - Steel

Sandsteel Mainspring for Elgin 12s Movements, Factory No. 1720, steel, new in frail envelope. See images for precise mainspring specifications and further details. 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.