New environmentally friendly refrigeration equipment such as air conditioners and refrigerators use refrigerants like R290 and R610A. These refrigerants have advantages such as being environmentally friendly and not depleting the ozone layer. However, they are classified as flammable gases. Relays used in such equipment are required to have explosion-proof properties and must comply with the testing requirements of the IEC 60079-15 standard. The printed content includes "Ex nC IIC Gc".