Fangrui Product Details 1. Gl09 4g Version 8 Channel Gsm Alarm Security System Module 2. Multi-band Support: Dc 5v-16v Power Input, 8 Alarm Detection Channels, Users Can Set Different Content For Each Alarm Information Channel. You Can Choose The Alarm Input Port As Nc Or No. 2. The Built-in 4g Module Can Work Anywhere In The World Through 4g, 3g And Gsm Networks. 3. Easy To Operate And Use: We Have Customized An App That Supports Iosandroid Systems, And You Can Set It Up Just By Sending A Text Message Through The App. 4. Multiple Groups Of Numbers Can Be Set: Up To 6 Groups Of Called Numbers Can Be Set. When The Alarm Input Has A Trigger Signal, The Alarm Information Will Be Sent To The Alarm Number, And The Alarm Number Can Also Be Dialed Directly. 5. Low Voltage Alarm Function: Low Power Sleep Mode Design, Real-time Detection Of Battery Voltage And Low Voltage Alarm, Suitable For Battery-powered Applications. 6. Short Circuit Alarm: Input Is Switch Signal. When The Input Port Is Short-circuited With The Ground (gnd), An Alarm Message Will Be Sent To The Preset Mobile Phone Or The Set Alarm Number Will Be Dialed. The Content Of The Alarm Message Can Be Determined By You 7. This Product Can Be Powered By Dc Power Supply Or By Battery (battery Not Included)