Link Belt Flange Bearing F3U231N,  1-15/16 bore with set screws, approximately 5-3/4 square flange with 2-1/4 overall height, approximately 4-3/8 square mounting bolt pattern for 1/2 inch screws.   These bearings are were originally lightly used on the rollers of a package handling cornering conveyor.   May be some surface rust and dust from use and storage.