Danner (2) Pondmaster Model 2-18 Rigid Replacement Pre-Filters for 250-1800 GPH Pumps Works great for pumps in the 250 GPH thru 1800 GPH range Rigid prefilter Helps to protect the pump from taking in large particles that may clog the intake or damage the impeller It attaches to the intake of Pondmaster magnetic pumps Part Number: 12595