Proven in more than 1 million vehicles! Metal & rubber. A/C repair kit with leak detector. Repairs metal leaks in: evaporator, condenser, compressor, accumulator, receiver/dryer. Seals rubber leaks in: O-rings, gaskets, hoses. Interdynamics R-134a Super Seal contains chemicals that are activated by moisture to form a patch as the refrigerant passes through a leak. These chemicals seal leaks in the condenser, evaporator, accumulator, and compressor. Super Seal contains conditioners and sealers that penetrate and rejuvenate O-rings, gaskets and other rubber connectors to prevent leakage. It also contains a drying agent to eliminate moisture and a dye to mark larger leaks. Larger leaks where the refrigerant charge is lost within two weeks may need to be manually repaired. Product of USA, China.