The GSM-CTL is a wireless GSM remote control switch that connects to the GSM cell phone network.
It has seven independent relay switches, and the NO. 1 Relay switch is activated by calling its cell phone number, it will reject the call without answering and switch on the device connected to it, then there are no call costs incurred when dialling the unit, it will recognise an authorised telephone number calling it and reject the call without answering.
It has other one relay independent relay switches which can be switched on or off by sending the GSM-CTL an SMS text message.

Specifications:

Real-time & interactive control
2 channels 250V 30A 50 Hz relay contacts
Works with GSM phones
Operating temperature (-25...+60 ° C)
Relays operates almost every appliance
Small standby power (< 10mA 12V)
Relay memory after power failure
Optional password to keep the system at safety operating mode.
Remote Password change
Two operating mode optional ( remote setting with GSM phones)
One relay is woking with the phone calling, and others working with the SMS
Commands can added to GSM-phone number for raeady made commands
Working voltage is at 9~12V AC /DC.
Applications:

Applications include the remote control of heating in holiday homes, lighting, engine pre-heaters, aviation engine heaters, irrigation systems, water well pumps, pumping stations, cabin heaters, resetting of remote servers, arming and disarming security systems, access control of gates and garage doors.