HR Mainspring SA410 for 16s Illinois Factory No. 47315 - Alloy

HR Mainspring SA410 for 16s Illinois, Factory No. 47315, T brace, 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.