TotalPond Replacement Filter Pads for the Universal Pump Filter Box (MF13010) and Complete Filter Kit with Pump (MF13015) Replacement Filter Pads for 52231 and 52229 contain 2 filter pads for use in the Universal Pump Filter Box or Complete Filter Kit with 300 GPH Pump. Includes 2 rectangular filter pads, 1 coarse and 1 fine. We recommend changing filter pads yearly for optimum cleaning performance. 90 day warranty