Long-Life Carbon Block Cartridges have a polyolefin-bonded powdered activated carbon (PAC) filter. Surface area of 2.2 million sq ft. Removes tastes, odors, chlorine, and sediment. Contains approximately 12 oz of carbon. PP end caps and outer wraps. Maximum temperature is 100°F (38°C); maximum differential pressure is 150 psid. For optimal performance, change cartridges at 25 psid.