4 GPM 4400 PSI Washer Pump 1 Inch Shaft for Cleaning Indoor and Outdoor Walls, Roads, etc Feature: Removable internal relief valve, adjustable pressure Pressure flushing pumps add water pressure to clean walls, sidewalks and vehicles, increasing cleaning capacity Pressure flushing pumps are made of high quality materials with high strength and long service life Specification: Maximum flow rate: 4 GPM Maximum pressure: 4400 PSI Connection port size: 1 inch Note: To make sure the product is the one you need, please check the PSI, GPM, size and other information of the product before purchasing Package includes: 1 x pressure washer pump 1 x installation kit