4G with one SIM slot for cellular WAN 1 x Fast Ethernet port 3 x Digital Input 2 x Digital Output 1 x (RS-232 or RS-485) Serial port Supports Modbus TCP/RTU/ASCII Master/Slave Access Durable zinc-plated steel case is corrosion-resistant to ensure device longevity -30 to 70°C operating temperature to resist harsh environments Wide Voltage Range Input: DC 9-36V DIN-rail mounting allows for optimal device placement.