This product, with TaiWan military technology GSM module with voice-activated automatic pull back function, can be installed in home, companies, shops and warehouse. It is more, this product is with compact size, , stabke performance. It is eay to operate withour install, and can be operated by remote control etc...

    * Device will start work while pluging, then it can auto answer any incoming call.
   Function setting:
    * Send SMS "GDM1" to start voice control. When there is any sound around, the device will call your mobile.
    * Send SMS "GDM2" to stop voice control function.
    * Send SMS "SJ**" to set voice control call back inerval.
   Note:
    * This product dont need any charging. Power from pluging.
    * If the product cannot Auto-answer, please check your SIM card, this machine using GSM network.
    * Before usage, check network signal first.
    * Please use a new SIM card to make sure security and confidentiality.
   Network:
    * GSM900MHz/DCS1800MHz
    * GSM850MHz/DCS1900MHz
 Quad-band optional,  please choose the network you need before ordering. If not, we will choose one according to your shipping address.