USR Mainspring for N.Y. Standard 0s No. No. 6133 - Steel

USR Mainspring for N.Y. Standard 0s movements, Factory No. 6133 (and perhaps 2133), steel, new in envelope. I've looked far and wide to see if there was ever 2133 mainspring for NY Standard movements but the answer is no, so I'm going with the 2133 bring a misprint. 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