NuVigor Mainspring #298 for Illinois 16s Factory No. 47309 - Steel

NuVigor Mainspring #298 for Illinois 16s 60hr movements, Factory No. 47309, steel, new in  envelope. See images for precise mainspring specifications. I likely have several of these (including one in a unmarked envelope - it came that way) 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.