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 where GSM signal is available Supports setting up to 5 groups of master numbers Can control 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 directly controlling electrical appliances, it can only be used with other control devices 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. 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 display must be enabled, and the SIM card must have sufficient balance to receive calls and messages 6. Do not install the GSM switch in a metal enclosure or tin container 7. In areas with weak signal strength, SMS control may be less effective, 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: Allow 1-3mm variation due to manual measurement. Please ensure you are comfortable with this before purchasing Due to differences in monitor displays, the image may not accurately reflect the actual color of the item. Thank you! Package Contents: 1 x GSM Switch 1 x User Manual