he R-134A Sub-Zero Synthetic Auto A/C Recharge 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. Reusable push-button dispenser with gauge and temperature dial indicator.