This is a NEW magazine spring for the Winchester 1866/1873/1894/ 1892 rifle. It fits the .38 and .44 cal in the 1873 and 1892 models. This spring also fits all of the 1894 rifle calibers and the Marlin large cals. It comes with instructions on how long you need it to be carbine and Rifle models. It measures 40 inches uncut.