Environmental Water Systems | Heater Guard 5 micron pre-sediment filter and 100% FDA-approved food-grade polyphosphate. Reduces sediment and inhibits scale formation on heating element surfaces. Reversible flow for any installation. City water or well water*. Features & Benefits World-class EWS quality and performance. Keeps your water heater clean and easy to maintain. Comes completely assembled for quick and easy installation. Meets or exceeds all compliances. Made in the USA. Model #: EWS-HEATER-GUARD-3/4 Height: 25 3/4″ Diameter: 5 1/4″ Weight: 7 lbs. Flow Rate: 1" inlet & outlet, up to 9.5 gallons per minute Filter Capacity: up to 1 year¹ Filter Replacement #: BB-Guard-Filter-3/4 Filter Housing: BPA-free, phthalate-free blue plastic Filtration Media: 20″ 5 micron pre-sediment and 100% FDA food-grade polyphosphate