Pennsylvania Mainspring for Waltham 12s No. 2224A - Steel

"Pennysylvania" Mainspring made by Waltham for Waltham 12s movements, Factory No. 2224A, steel, new in frail envelope. See image for further details. Why Waltham chose to call these "Pennsylvania" instead of just the typical "Unit Resilient Main Spring" may forever be a mystery. I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a marginally adequate job of representing the item