Marathon Mainspring #206 for Elgin 4/0s No. 4789 - Steel

Marathon steel mainspring No. 206 for Elgin 4/0s movements, Factory No. 4789, new in envelope. See images for precise mainspring specifications. I specialize in hard to find watch parts so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.