Penray says its three Pencool air conditioner filters will last 3,000 hours. Power Fleet Need-Release Extended Life Cooling system filters are compatible with all conventional, extended-life, long-life, OAT, NOAT, HOAT, GO-5 and automotive coolants. For use with liquid cooling, the NF2999 coolant filter series has an eopoxy-coated inner shell and outer shell of baked enamel. The company says it is guaranteed for 1,500 hours and has been tested at 350 degrees F without degradation. NF2999 fits standard filter brackets for Detroit Diesel, Caterpillar, Cummins and Ford engines. The NF3000 with Stabil-Aid filters combine a filter with one pint or more of corrosion inhibitor and coolant stabilizer and is compatible with all antifreezes.