APEC FI-CS-2500P Replacement Filter for CS-2500P Water Filtration System US Made highest trustful filtration capacity of similar products. Trouble-free installation with quick twist and lock connection for easy filter replacement. Bacteriostatic for the reduction of heterotropic bacteria. Scale reduction feature to reduce scaling and corrosion. High flow low restriction design to support maximum 1.67 GPM (6.321 LPM) flow rate.