Marco Mainspring #2737 for Universal 231, Font 206, 206-1 - Steel

Marco Mainspring No. 2737 for Universal 231, Font 206, 206-1 caliber movements, steel, new in envelope. See images for precise mainspring specifications and further details. 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.