Elgin DuraPower Factory Mainspring for 15/0s Grade 557 No. 6003 - Alloy

Elgin Factory DuraPower Mainspring for 15/0s movements, Factory No. 6003, alloy, new in envelope. You can pick from one of several of available strengths for the 15/0s movement from the drop-down list. I likely have several of these in each strength so the one you get may differ 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.