CR Mainspring #512 for NY Standard Mainspring for 0s No. 6133 - Steel

Charles Robert Mainspring #512 for NY Standard 0s movements, Factory No. 6133, T-end, steel, new in frail or replacement envelope. Dennison 6 x 7 x 13-1/2, width, strength, length. These are virtually identical to the Waltham 2221 in case anyone needs that - they'll work swimmingly. 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 and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.