Universal 4.5-in replacement filter fits A. O. Smith whole house system AO-WH-PREL. Use only certified, genuine A. O. Smith filters for continued contaminant removal and system performance.
Longer lasting appliances - whole house filter system designed to reduce sediment from every tap.
IAPMO tested and certified to NSF/ANSI standard 42 for materials. 20 micron filtration - reduces sediment smaller than the human eye can see.
Replacements made easy - no plumber necessary. Replace filter every 3 months. Large capacity (4.5") filter is perfect for household sizes 4 or more people.
