Use mobile phone making call or sending message to this GSM socket to switch on/off the power socket so that to control the electrical appliances It works in any places with GSM signal available It can control water heaters, electric motors, electric doors, lights, rice cookers and other appliances Note: 1. Can only control the power supply switched on or off, do not have other functions. 2. In addition to work directly with current electrical appliances, only if other control or button electrical appliances with memory function can use this products. 3. SIM card requirements: Global GSM standard SIM card can be used, currently does not support 3G or CDMA card, please activate the SIM before insert the device. 4. It is recommended that customers buy an SIM card which is answering free, so it only cause the auto answering messages fee. 5. Incoming Caller ID display must be turned on, make sure that SIM card has sufficient balance in order to call and send text messages. 6. Do not place the GSM switch in the tin trunk or metal enclosed environment. 7. When the signal is weak in some environment, it will make SMS controlled no that Perfect and this is normal. Plug Type:UK plug,it applies to Malaysia, the United Kingdom and so on. voltage:AC110-220V Colour:White Material:plastic Package Contents: 1 x GSM Power Socket