This Annovi Reverberi Pump, SRMW2.2G26-EZ, 2.2GPM@2600PSI spins at 3400 RPM in a direct drive system coupled with a gasoline engine. The matching flange provides convenient connection to most 7/8” shaft 4 - 7 HP engines. The hollow shafted pump includes a built-in pressure control valve, and chemical injection system. Comes with thermal relief valve and easy start valve (EZ). This pump fits vertical shaft models only. Pump shaft key is not included (you can get one from your local hardware store 3/16" square key X 1" long), you may also need to get new bolts to go through the pump, frame & engine. Your local hardware store will carry these. Here is the most common size bolts needed: 5/16"-18 x 2-1/2" (Qty. 2), 5/16"-18 x 3-1/2" (Qty. 1).