Elgin Factory Mainspring for 16s 23j Motor Barrel No. 4931 - Steel

Elgin Factory Mainspring for 16s 23j Motor Barrel movements, Factory No. 4931, steel, new in envelope. Has the typical Elgin DB&H end.  See images for further details. I see these pretty infrequently so get them when you can. While all mainsprings should be cleaned before use, the Elgin springs can be especially sticky and goopy, and these are no exception. 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.