PM Mainspring No. 202 for Elgin 8/0s No. 5219 - ONYX Steel

PM Mainspring No. 202 for Elgin 8/0s, Factory No. 5219, ONYX Steel, new in double envelope and foil. See image for precise characteristics. 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.