4G with dual SIM slots for cellular WAN failover redundancy 2 x Gigabit Ethernet ports 1 x Digital Input 1 x Digital Output 2 x (RS-232 or RS-485) Serial port 1 x USB 2.0 and Micro SD slot for device log information 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. D-Link Corporation, No. 289, Sin Sin Road, Jhonghe City, Taipei County 235, Taiwan (R.O.C.), Podpora: https://www.dlink.com/cz/cs/support