Whole House 3-Stage Water Filtration System, 1/2" port. Works with standard 10" filters. Build in USA. 1st stage: Premium Quick-Connect 5 micron sediment filter. Dust, dirt, silt, sand, rust and scale particles are trapped here in a filter which also extends the life of the system. 2nd stage: Premium 10" GAC Granular Activated Carbon filter removes chlorine, radon, VOCs (volatile organic compounds) and other common chemicals. This filter also removes cloudiness, offensive odors, colors and unpleasant tastes. 3rd stage: 10" Premium CTO Carbon Block filter removes chlorine, VOCs (volatile organic compounds, including insecticides, pesticides and industrial solvent). Taste improvement. Unit comes with 3 pre-installed filters and one extra filter set. Filters need to be changed every 3 months. This is regular 10" filters which you can find online or locally at HomeDepot. Connection: 1/2" thread port. Working pressure: 20 to 100 psi water pressure.