1、Smart Chip: Smart temperature humidity alarm adopts GSM 3G 4G network communication, built in microprocessor to monitor the value of power supply voltage, measurement range 0‑36V, regardless of distance. 2、SMS Reminder: The environmental monitoring alarm supports 10 authorized user numbers, which can receive alarm SMS when alarming, among which the last 5 authorized numbers can also receive alarm telephone reminder. 3、Periodic Reminder: Temperature humidity alarm can be set to automatically report the current status to the first user number at a fixed point every day or periodically, and the alarm history can be checked remotely via SMS. 4、Easy to Upgrade: Modular structure design, GSM 3G 4G network upgrade can be achieved by simply replacing the communication module to upgrade the network, support wall mounting as well as DIN 35mm industrial rail mounting. 5、For Modbus Protocol: Support for Modbus RTU Over TCP and for Modbus TCP protocol, can connect to cloud platform for real time monitoring through network. The built in rechargeable battery can continue to work for 8 hours in case of power failure. Item Type: GSM Environment Alarm Material: Metal Power Consumption: Standby: 20mA at. 12V; Maximum Power Consumption: 150mA at. 12V GSM 3G 4G: GSM Frequency: 850/900/1800/1900 MHz (Default) SIM Card Interface: Support 3V SIM Card External Antenna: SMA Antenna Interface, 50 Ω Supported Protocols: for Modbus RTU Over TCP Protocol, for Modbus TCP Protocol Built in Battery: 3.7V/900mAh Lithium Battery X1 (Built in), Lasting For 8 Hours Working Temperature Range: - 10 ℃ - 60 ℃ Operating Humidity Range: Relative Humidity 95% (No Condensation) Equipment Size: Approx. 70mm x 88mm x 30mm (Length x Width x Height) 1 x Alarm 1 x Antenna 1 x Power Adapter 1 x Instruction