Elgin DuraPower Mainspring for 5/0s Grade 870 movements - Alloy

Elgin Factory DuraPower Mainspring for 5/0s Grade 870 - PUW 1260 based 17j, sweep second calendar movements, alloy, new in envelope. See images for further details. These are tough to find in factory Elgin. 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