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Isopure Water

Isopure Water (ISO-4PK) Reverse Osmosis RO 4 Filter Replacement Set

Product Code ISO-4PK - 1/4" NPT

$18.99
per 
Shipping calculated at checkout.

A full 4 piece replacement set for a standard/conventional reverse osmosis system. Including the following:

  • ISO-RO5
  • ISO-RO4DI
  • W-525
  • W-425
  • AND MANY OTHERS

Four set package includes:

  • one GAC cartridge filter
  • one carbon block 5 or 10 micron filter
  • one sediment 5 micron filter
  • one post inline GAC filter
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"

*NOTEA 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.