"1. Dual-SIM 4G/3G/2G cellular connectivity 2. RS232/RS485, LAN/WAN, Wi-Fi interfaces 3. Industrial-grade reliability with auto-recovery 4. Wi-Fi b/g/n with AP, Client, Repeater, Bridge modes 5. VPN support (PPTP, L2TP, IPsec, OpenVPN, GRE) 6. Advanced networking (NAT, Firewall, QoS, DDNS, SNMP) 7. Modbus RTUTCP conversion and transparent protocols 8. Remote management (Web, CLI, SSH, HTTPS) 9. Compact metal industrial enclosure"