Marco Mainspring #478 for 8/0s Hamilton Movements No. 7221 - Steel

Marco Mainspring No.478 for 8/0s Hamilton Wrist Watch movements, Factory No. 7221, steel, new in envelope. Could also very well fit in other models as well. 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.