This Annovi Reverberi Pump, RMW2.5G25D, 2600PSI@2.5GPM is a quality and cost effective replacement for factory replacement pumps. It is designed to fit most vertical Devilbiss units and as a replacement to Excell pump PK16862. It will not work with Karcher brand pressure washers. It is a radial axial pump with the popular 3 bolt pattern. It is also important to note that this pump does not include a shaft key and may require new bolts to go through the pump, both of which may be sourced at a local hardware store. Here are the most commonly needed bolts: 5/16"-18 x 2-1/2" (Qty. 2) 5/16"-18 x 3-1/2" (Qty. 1).