This high quality, affordable activated carbon filter is compatible with Sub-Zero refrigerators manufactured in 2011 or later and select LG® refrigerators. Utilizing a high quality carbon block, the porous structure provides absorption and reliable protection from substances that don't belong in drinking water. The filter allows useful minerals and fluorides to remain while harmful particles are filtered out. Tested and certified by NSF International to ensure every aspect of the filter is on par with their rigorous standards.