Aries (AF-20-1046-BB) 20"x4.5" Big Blue Coco GACAries Filter Works AF 20 1046 BB 20"x4. 5" Big Blue Coconut Shell GAC Filter Granular activated carbon from coconut shells for whole house chlorine, taste, and odor reduction in standard 20 inch Big Blue housings Coconut Shell Carbon 20" x 4. 5" Whole House WHY IT WORKS Premium coconut GAC for superior adsorption Coconut Shell Carbon Higher micropore density than coal based carbons means better chlorine removal and longer contact time with