The TIF TIFRX1A Electronic Refrigerant Leak Detector detects or sniffs R12 & 134A known as freon, this leak detector also works on all other types of refrigerants as well. Refrigerant leak detectors are a specialty tool that no repair shop should do without, A/C repairs can be very expensive and mis-diagnosed automotive A/C repairs are a leading cause of come backs in the automotive repair industry. Professional auto technicians that use a quality freon leak detector like this one can help insure that the repair is performed correctly the first time.