Simpson Cleaning 90027 Vertical Pressure Washer, 3100 Psi Direct drive vertical axial pump, 7/8shaft, thermal relief valve, SAE gas engine flange, threaded M22 pump outlet connection Universal to fit most brands/models Precision polished stainless steel pistons for improved seal life, dual oversized radial ball bearings for better wear and friction resistance, and integrated unloader with easy-start feature Pre-sealed with oil inside pump Patent Pending PowerBoost Technology to enhance cleaning performance