It will respond to all halogenated (contains Chlorine of Fluorine) refrigerants. This includes, but is not limited to:
CFCs e.g.R12, R11, R500, R503 etc.
HCFCs e.g. R22,R123, R124,R502 etc.
HFCs e.g. R134a, R404a, R125, 1234YF etc.
Blends such as AZ-50. HP62. MP39,etc.

Technician Parameter:
Operating temperature: 0℃-52℃ (30℉ to 125℉);
Maximum sensitivity: 0.21oz/yr, for all halogenated refrigerants;
Battery life: Approximately 50 hours normal use;
Response time: Instantaneous ;
Operating mode: Continuous, no limitation;
Fixed probe length:7.87 (in);
Dimensions:9.01*2.56*2.56 inches ;
Preheating time: approximately 6 seconds;
Reset time: 2 to 10 seconds;
Power supply: 6V DC, 4 AAA alkaline batteries.