Illinois Factory Mainspring #47371 for 6/0s hunting movements - Steel

Illinois Factory Mainspring Factory No. 47371 for 6/0s hunting wrist watch movements, steel, new in frail or even cut envelope. One of the beautiful thing about factory mainsprings is that they pretty much always fit. See images for 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.