The YG115/YG120, GFCI (Ground Fault Current Transformer) switch, device used for electrical safety protection, primarily to prevent electric shock and electrical fires. Highly sensitive current detection function. Once leakage or ground fault is detected in the circuit, the power supply can be quickly cut off, effectively preventing electric shock accidents. In addition, GFCI switches are also waterproof and moisture-proof, and are suitable for use in humid environments such as bathrooms and kitchens, providing users with a safer and more reliable electrical environment.