This Stevens manufactured breech block stop screw spacer is for the Favorite single shot falling block rimfire rifle which has the 1st variation (7 o' clock style) extractor and mounts under the breech block stop screw on the top flat of the breech block. This spacer is in very good condition exhibiting a brown patina with light wear. (file photo)

Note: this part is commonly found on 1st & 2nd variation receivers which were manufactured from 1894 through 1898.