Marco Mainspring 580P for 6/0s Illinois Factory No. 47364 - Alloy

Marco Mainspring 580P for 6/0s Illinois Open Face 1st and 3rd models, Factory No. 47364, alloy, new in envelope. See images 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.