APEC Essence standard capacity pre-filter set is made with high quality filtration components to protect and prolong the lifespan of your reverse osmosis system. Premium quality filter set lasts over 6 months for high performance impurity removal. These standard size filters are 10 inch and compatible with all standard size under counter reverse osmosis systems. 1st stage: 5 micron polypropylene filter to remove sediment, particles, and rust. Prevent sediment from building up and clogging the filters and the system. 2nd and 3rd stage: 10 micron extruded carbon block filter to remove chlorine, taste & odor at a fast flow rate. Improve water taste, protect the life of the ro membrane and enjoy chlorine free water. Compatible for apec essence reverse osmosis drinking water system and all other standard size under counter reverse osmosis systems on the market. About APEC Water Systems For over 20 years, APEC Water Systems has been an industry leading manufacturer who specializes in high performance ro systems. As the original manufacturer, we have dedicated a knowledgeable and sincere team that is committed to providing customer SATISFACTION in hopes to bring many years of enjoyment and good health for you and your family. APEC Water does not distribute or sell our products to any 3RD party sellers. Please purchase genuine apec water products from here or apec water directly for authenticity.