HR Mainspring SA416 for Illinois 16s No. 47331 - Alloy

HR Mainspring SA416 for Illinois 16s movements, Factory No. 47331, alloy, new in envelope. See image for 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.