If your radiator has become clogged, your heater core will eventually become clogged also. Unfuiltered coolant from the engine flows through the heater core as well as through the radiator. Rust scale and gasket material can collect in the heater core forcing one to replace the heater core at great expense. This gano filter installs in teh hose that connect between the engine and the heater input. Once installed, it catches rust scale and gasket parts before they can clog the heater core. This is a permanenet accessory that can be disassembled, cleaned and replaced.