Bacteriostatic Composite Carbon Block 20" Whole House Filter System Replacement Filter Cartridge Suitable for all Big Blue or Big White 20″ x 4.5″ Filter housings.  

• Functional carbon block technology 

• coconut shell carbon 

• Silver nano technology

• 10 micron

• antimicrobial protection carbon block

• greatest chlorine, taste and odor reduction 

• Ideal for uses on Town, Tank or Dam Water