Each preassembled rite size has a patented ribbed back that evenly distributes carbon for maximum water to carbon contact. No bypass, no tea bag effect. No messy assembly required. Changes in an instant. Delivers Two Full Ounces Of Activated Carbon Filtration And 45% More Mechanical Filter Area. Larger Polyfiber Filter Pad. Highest Grade Magnum Carbon Removes More Pollutants. 3 PACK