This AR Residential Plunger Pump (SRMW24G28-EZ) is for vertical gas engine driven pressure washers. It flows 2.2 gallons per minute at 2,800 PSI and 3,400 RPM. This pump mounts directly on to the engine shaft by using a keyed hollow shaft connection system. The mounting flange provides a convenient connection to most 7/8? diameter shaft vertical gas engines in 4 - 7 HP and fits most OEM carts. This pump includes a built-in pressure control valve, downstream chemical injection system, EZ start valve and thermal relief valve. The seal system uses a high and low pressure seal.