【CERTIFIED AND TESTED】: Tested and certified by NSF/ANSI 53 & 42, reduces chlorine, taste and odor, particulate, lead, cyst, benzene, carbofuran and endrin. 【REPLACEMENT CYCLE】: To achieve optimal performance, change your filter every 6 months or 300 gallons. 【PREMIUM MATERIAL】: Uses high-grade natural coconut shell activated carbon block as filtration material, which features better adsorptive ability and better filtration performance with microscopic pores.