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, enabling control of electrical appliances Operates in any location with available GSM signal Supports setting up to 5 master phone numbers Can control devices such as water heaters, electric motors, electric doors, lights, rice cookers, and other appliances Note: 1. Controls only the on/off function of the power supply; no additional functions are supported 2. Besides direct connection to electrical appliances, it can only be used with other controlled devices or button-operated appliances that have memory functionality 3. SIM card requirements: A standard GSM SIM card is required; 3G or CDMA cards are not supported. 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 message auto-reply fees will apply 5. Caller ID must be enabled on the SIM card, and the card must have sufficient balance to receive calls and messages 6. Do not install the GSM switch in a metal enclosure or enclosed metal environment 7. In areas with weak signal strength, SMS control performance may be reduced; this 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. Ensure you are comfortable with this before purchasing Due to differences in monitor displays, the image may not accurately represent the actual color of the item. Thank you! Package Contents: 1 x GSM Switch 1 x User Manual