Paulson Mainspring for Waltham 6s No. 2217 - Steel

Paulson Certified No.3 Mainspring for Waltham 6s, Factory No. 2217, Steel, new in envelope. The box these came in list them as a Dennison 10 x 4½ x 16. 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.