Rtu42 Home Security GSM Alarm System SMS Controller USB Remote 4 Input 2 Output GSM SMS Remote Controller, SMS Relay Switch, supports Android & ios APP 1 relay output (240VAC@3A) can be switched ON/OFF by sending a SMS text; 1 relay output (240VAC@3A) can be switch on 4minutes if any inputs triggered; 4 Alarm logic inputs, NC or NO and EOL is optional; 3 SMS Alert numbers and 5 auto-dial numbers can accept to the alarm message; Optional Accessories: Water Overflow Level Sensor, Oil Overflow Level Sensor, Water Leak Sensor, Temperature Sensor, Door Sensor, PIR Motion Sensor, Smoke Sensor,