Metric Specification Shaft Size / Inside Diameter1.750" (1-3/4 inches) Rotary Head Style US Seal Type E (Equal to John Crane Type 1) Seal Head Dimensions2.375" Outside Diameter (OD) x 2.000" Operating Height Stationary Seat Style Cup Mounted Seat (US Seal Type 1) Stationary Seat Dimensions2.500" Bore / Seat OD x 0.500" Thickness Standard Seal Faces Carbon (Primary Ring) vs. Ceramic (Mating Ring)Standard ElastomersBuna-N RubberHardware ComponentsStainless Steel Metal Parts & Single Coil Spring