Elgin DuraPower Factory Mainspring for 20/0s grades 900, 901, 902 - Alloy

Elgin Factory DuraPower Mainspring for 20/0s grade 900 thru 902 movements, alloy, new in sealed envelope. I likely have of these the one you receive 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