Shaft O.D. or Seal I.D.: 5.09 inch (129 mm) Housing I.D. or Seal O.D.: 6.35 inch (161 mm) Axial X-section: 0.4060 inch (10.31 mm) Material (ASTM Abbreviation): Fluoroelastomer (FKM) (optional feature); Nitrile (NBR) (optional feature)