The 3-Stage Whole House System easily attaches to house plumbing. This filtration system comes with regular 2.5″ x 10″ slim housing. Comes with an extra spare set of filters (3 pcs). 1st stage: 10″x2.5" 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″x2.5" 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″x2.5" Premium CTO Carbon Block filter removes chlorine, VOCs (volatile organic compounds, and industrial solvents). Taste improvement. Connection: 3/4″ thread. included an extra set of filters as a replacement. You need to change filters every 4-6 months. included: 2 nipples 3/4″ x 3/4″, 2 of on/off valves. Housing Color - Solid Blue. Assembled in USA.