The Omnipure K-Series K2586 inline filter is a GAC phosphate inline filter. This filter has 1/4" NPT that make the filter really easy to install and replace. This filter can go in ice makers, refrigerators, beverage equipment, drinking fountains, under the counter systems, R.O.Systems and in conjunction with purification systems. This filter also helps in the removal of taste, odor and chlorine along with 6 ounces of polyphosphate scale inhibitor. Dimensions: 2" W X 10" L Flow Rate: .5 GPM Maximum Pressure: 125 PSI Maximum Temperature: 100 F Service Life: 6 Months Filtration Media: Polyphosphate - Scale Inhibitor National Pipe Thread (NPT) Size Measured Against a Ruler* Actual Diameter (Inches) National Pipe Thread (NPT) (Fractional) 0.405" 1/8" 0.540" 1/4" 0.675" 3/8" 0.840" 1/2" *NOTE: A very common misconception is that a 1/4" NPT measures as 1/4 inch on a ruler or tape measurer. However, that is not the case. NPT will measure larger in diameter. Above is a sizing reference to help clarify.