Provides annual protection against costly water heater scaling and sediment build-up. Siliphos® Polyphosphate Media prevents water hardness from scaling on flash heating surfaces. A 5-micron filter reduces sediment, which can cause additional scaling throughout the hot water line. The unique micro-fiber filter construction delivers higher filtration efficiency and flow rates. Ideal for indoor and outdoor installations. Features a 3/4” NPT inlet/outlet with a differential filter change gauge for peace-of-mind.