The PURA UV20 Series is designed to provide disinfected water at a flow rate of 8 - 10 gallons per minute. The Pura UV-20-3 CB20XSD combines ultraviolet filtration with a five micron sediment filter & a ten micron carbon block filter & UV lamp useful for most standard whole house water filtration needs. This system is ideal for whole house water treatment. These are good, free-flowing units that handle up to 10 gallons per minute of flow. Port size of all vessels is 3/4".