RTU5023 Temperature Humidity Alarm GSM 3G 4G Wireless SMS Alert Power Outage Failure Alarm Environmental Monitor AC 100‑240V 4GL-A US Plug Item Type: Temperature Humidity AlarmMaterial: Metal Power Consumption: Standby: 20mA at 12V; Maximum Power Consumption: 150mA at 12V GSM/3G/4G: GSM Frequency: 850/900/1800/1900MHz (default) SIM Interface Support: 3V SIM cards External Antenna: SMA antenna interface, 50 ohms Support Protocol: For Modbus RTU Over TCP protocol, for Modbus TCP protocolMain Machine: -40~+80°C, RH: 0-100% Sensor: Temperature measurement range -40°C~80°C, accuracy ±0.5°C, humidity measurement range 0~99.9%RH, accuracy ±3%RH Built in Battery: 3.7V/900mAh lithium batteryx1 (built in), can work for 8 hours Operating Temperature Range: -10°C~60°C Operating Humidity Range: Relative humidity 95% (non condensing) Device Dimensions: Length: Approx. 70mm/2.76in, Width Approx. 88mm/3.46in,  Height: 30mm/1.18in