The ATP B3J-S Clockwise, Mechanical Seal pump is a high pressure, hydraulically driven, 4 x 3 (inlet is 4 ID, 5 OD) Grooved water pump with a 13.5 Impeller. This pump is driven directly by a SAE C Mount, 1 1 / 4 14 tooth Splined Shaft hydraulic motor coupled to the water pump shaft with a 116-M10176 coupling. When operating at 3,000 RPM this pump is capable of 1,150 GPM at 208 PSI and is primarily used for Off Road , larger mine tank equipment. PLEASE NOTE: This pump requires a 5 coupling on the inlet. We recommend using a 5 x 4 Grooved Reducing Coupling (251-500x400) to use this pump with normal 4 intake plumbing.