| Model | Zyxel USG FLEX 100 |
| 10/100/1000 Mbps RJ-45 ports | 4 x LAN/DMZ, 1 x WAN |
| USB 3.0 ports | 1 |
| Console port | Yes (RJ-45) |
| SPI firewall throughput | 900 Mbps |
| VPN throughput | 270 Mbps |
| VPN IMIX throughput | 100 Mbps |
| IPS throughput | 540 Mbps |
| UTM throughput (Anti-Malware and IPS) | 360 Mbps |
| Max. TCP concurrent sessions | 300,000 |
| Recommended gateway-to-gateway IPsec VPN tunnels | 20 |
| Max. concurrent IPsec VPN tunnels | 50 |
| Concurrent SSL VPN users | 30 |
| VLAN interface | 8 |
| SPI firewall throughput | 848 Mbps |
| VPN | IKEv2, IPSec, SSL, L2TP/IPSec |
| Power input | 12 V DC, 2 A max. |
| Max. power consumption | 12.5 Watt Max |
| Heat dissipation | 42.65 BTU/hr |
| Packing Dimensions (WxDxH) (mm/in.) | 284 x 190 x 100/ 11.18 x 7.48 x 3.94 |
| Packing Weight (kg/lb.) | 1.40/3.09 |