Features: Use a mobile phone to make a call or send a message to this GSM socket to switch the power socket on or off, allowing control of electrical appliances Works in any location where GSM signal is available Supports setting up to 5 master phone numbers Can control water heaters, electric motors, electric doors, lights, rice cookers, and other appliances Note: 1. This device only controls the on/off function of the power supply and does not have additional features 2. Besides directly controlling powered appliances, it can only be used with other controlled or button-operated appliances that have memory functionality 3. SIM card requirements: A global GSM standard SIM card is required; 3G or CDMA cards are not supported. Please activate the SIM card before inserting it into the device 4. It is recommended to use a SIM card with free incoming calls to minimize costs, as only auto-reply message fees will apply 5. Caller ID must be enabled, and the SIM card must have sufficient balance to receive calls and SMS 6. Do not install the GSM switch in a metal enclosure or tin box, as this may interfere with signal reception 7. In areas with weak signal strength, SMS control performance may be reduced, which is normal Specifications: Voltage: 110V-220V Current: 10A Rated frequency: 50Hz Power: 2200W Plug Type: UK/EU Plug Size: 100x65mm / 3.94x2.56 inches Quantity: 1 Piece Note: Please allow 1-3mm variation due to manual measurement Due to differences in monitor displays, the actual product color may vary slightly from images shown Package Contents: 1 x GSM Switch 1 x User Manual