RED TEK DyeCharge12 A/C Leak Finder (4 oz. can) Operation: Easy to use. Installs in minutes. Finds leaks fast. Lower Cost: Leaks can be found and repaired saving time and money. Compatibility: Compatible with most common refrigeration materials and lubricants including R134a, R12, metal components, mineral and synthetic(Ester and PAG) lubricants, seals, gaskets, hoses, compressors, and o-rings. Environment: Helps environment by reducing refrigerant emissions. Safety: Safe and easy to use, non toxic, non-clogging formula.