"This AR Pumps Pressure Washer Pump offers fast changeover, even in the field. Pre-plumbed and pre-tested. Fits 4-bolt engine face plates. Bolts not included use existing bolts from old pump to install new pump. U.S.A. Application Pressure washer pump, Fuel Type Electric, gas, Max. PSI 4,000, HP 12.5 electric, 16 gas, Shaft Diameter in. 24mm, GPM 4 1/2. Pre-plumbed and pre-tested Fits 4-bolt engine face plates Belt drive"