This plunger will pump up to 2.5 GPM at 3000 PSI. It spins at 3400 RPM in a direct system coupled with a gasoline engine. The matching flange provides convenient connection to most 3/4 inch shaft 1.1-5.5 HP engines. The hollow shafted pump includes a built-in pressure control value, and chemical injection system. With EZ easy start valve.