51 Series Motor Bi-Rotational Tandem Unit 2 Stages Sae 2 Bolt B Sec 7/8-13 Spline Shaft First Stage 2-1/2 Gear Width Housing Npt #20 1-1/4 Inlet Port Npt #20 1-1/4 Outlet Port Second Stage Bearing Carrier Blank Inlet Port Blank Outlet Port 2-1/2 Gear Width Housing Npt #20 1-1/4 Inlet Port Npt #20 1-1/4 Outlet Port Unported Port End Cover Extended Studs Top