Pro Products, LLC’s Poly Guard System is a complete scale and corrosion treatment solution. Each system has one refillable cartridge that contains 24 ounces of extended release crystals, which will treat 30,000 gallons (113,562.35 liters) or for up to six months. Also included: a clear, 10-inch filter housing with a pressure release button, housing wrench and a filter-replacement reminder sticker. The crystals prevent hard-water scale, corrosion and iron build-up in water systems, equipment and appliances by forming a protective coating on metal and plastic surfaces and holding minerals in solution before they can cause discoloration on appliances and plumbing fixtures.www.proproducts.cominfo@proproducts.com