Waterbury Model Y Mainspring Made by Waltham - Steel

Waterbury / New England Mainspring for the Model / Grade Y watch, Factory made by Waltham, steel, new in envelope. See images for further details. Hole End mainspring that measures a Dennison 12½ x 2. Waltham didn't mark them except for "Unit Resilient Main Spring" because they let the supply house mark them if they wished to do so. I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do an adequate job of representing the item.