Eliassof Bros & Co. "Regular" Mainspring for Waltham 12s Factory No. 2224A - Steel

Eliassof Bros & Co Regular Mainspring for Waltham 12s movements, Factory No. 2224A, blue steel, new in envelope. See image for further details. Yes, this is marked Waltham but these were not made by Waltham, although they may have been distributed by them at some point. I specialize is hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.