The easy way to tune up your air conditioner system without additional tools. It contains 12 oz. of 134a refrigerant, 2 oz. of PAG oil to lubricate and quiet noisy compressors. Stop leak to prevent refrigerant leakage and O-ring conditioner to improve durability. The easy-to-use recharge hose also contains a safety valve to prevent refrigerant from venting. Patented quick-couple fitting.