1/2" Screw Size 15/16" Flange O.D. Black Finish Push On Type Retainers Compare with: Auveco #9299, Car Pak # 75-4123, 754123, W&E #1052, Barnes / Kar # 35317, Crest / Midwest # CRX1148, Kent / Lawson # P32351, Wurth # 150159323, Disco # 991PK, 991B