Sub-Zero synthetic refrigerant kit has a specially designed formula featuring Cool Boost technology that helps a vehicle's A/C produce colder air. The approximately 17 oz. of R-134a and 1 oz. of additives are used to recharge a vehicle's A/C system, seal common leaks in rubber components, and help extend the A/C system's life by eliminating acid and moisture buildup. This A/C recharge kit comes with a reusable charging hose and gauge.