BESTFIT Mainspring 411M for ETA 734 thru 739, Eterna 710, Marvin 610 - Alloy

BESTFIT Mainspring 411M for ETA 734 thru 739, Eterna 710, Marvin 610 caliber movements and perhaps others as well including several non-automatic Wittnauer movements, white alloy, new in envelope.  See images for urther details and precise mainspring specifications. I likely have several of these so the one you get may differ slightly from the images. I specialize in hard to find watch parts so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.