The Frigidaire PureSource 3 water filter (WF3CB) produces cleaner, better tasting drinking and cooking water, including all dispensed drinking water, as well as the water used to produce ice. NSF 42, 53 & 401 certified to filter out contaminants: Tested and certified by NSF International against NSF/ANSI Standards 42, 53 and 401 in PureSource 3 for reduction of the claims on the performance data sheet.