The AO Smith High-Efficiency Reverse Osmosis Carbon Block Replacements J2 is a set of water filters designed for household use. Compatible with Aqua Optima brand systems, these filters are made of carbon material and offer 2 stages of filtration to remove contaminants such as chlorine, lead, fluoride, and sediment. With a capacity of 20.1-25 ft³, these filters are suitable for small kitchen appliances and provide clean water for your home. Made in the United States, this product ensures quality filtration for your peace of mind.