The Waterspecialist refrigerator water filter features filtration performance is comparable to the original brand. It is also certified by authority NSF 42 and 372. Far different from generic brand, Waterspecialist only adopts 100% superior coconut shell carbon block to improve taste and odor. Great filtration: Waterspecialist refrigerator filters can reduce many harmful substances in water including chlorine, taste and odor. This has been tested and proven by an independent third-party laboratory. Premium filter material: Waterspecialist selected BPA-free and food-grade filter housing that passed NSF 372 certification for lead-free filtration. We also adopt 100% coconut shell carbon block that contains larger surface area and more micropores than inferior carbon block. Thus, the filter cartridge can efficiently reduce chlorine, bad taste and odor.