Interdynamics Sub-Zero Synthetic Automotive Refrigerant R-134a (12 ounces) Replaces lost R-134a refrigerant and oil in automotive A/C system Formulated with COOL BOOST technology to provide up to 18% colder air System-safe leak sealer additive seals common A/C leaks in rubber hoses, gaskets and O-rings Eliminates moisture buildup and acid from A/C system to help extend A/C system life ACME threaded top