Elgin Factory DuraPower Mainspring for Series 660 No. 6330 - Alloy

Elgin DuraPower Factory Mainspring for Series 660 movements except for 666, Factory No. 6330 (the default is a 6330-.0029), alloy, new in envelope. If I have the other strengths (-.0027 & -.0031) they should appear as an variation so you can pick which one you want. See image for further details. I likely have several of these in each strength so the one you get 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