Swartchild Black Shield Mainspring #440563 for Elgin 8/0s Factory No. 5219 - Steel

Swartchild Black Shield Mainspring #440563 for Elgin 8/0s, Factory No. 5219, steel, typical Elgin DB&H end, new in envelope. See images for further details and precise mainspring specifications. 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