NuTemper Mainspring No.630 for 12s Hamilton 17-19j #1228 - Steel

NuTemper Mainspring No.630 for 12s Hamilton 17-19j, Factory No. 1228 for numerous 900 series models, steel, new in frail envelope. See image for further details. 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.