USG FLEX Firewall

Secure. Fast. Protection.


USG FLEX H series provides secure, fast protection with ground-breaking high performance for Virtual Private Networks (VPN) and Unified Threat Management (UTM), a multi-layered approach to protecting the Firewall, the network infrastructure and connected users by leveraging Zyxel’s high-performance hardware and state-of-the-art AI Security Cloud architecture.

Ultra High Performance

Ultra-high Performance powered by our next-generation multi-core hardware and Fastpath technology to create ultra-high efficiency. The USG FLEX H series can boost performance by up to 3x, optimizing utilization of its processors and allowing Zyxel to deliver superior performance to satisfy the needs required by demanding and high-speed networks.

Port Flexibility, Multi-G and PoE+

With 2.5 Gbps and 10 Gbps Port Speed options, The USG FLEX H also features software-defined ports, allowing you true flexibility in the configuration and tailoring of each USG FLEX H as required (WAN or LAN).

The USG FLEX H offers up to 2 x 30W PoE+ integrated ports*1 to help reduce complexity by simplifying installations and reduce install costs by allowing you to power devices like 5G Routers, latest WiFi, or appliances like VoIP Phones directly from the USG FLEX H itself.

Hassle free network management with Nebula.

Utilizing nebula, Zyxel’s centralised cloud management platform you can configure and deploy network and security devices centrally.

You can manage multiple devices and bring the information from them together, combining it to create a more effective defensive ring around the network.

AI-powered cloud cybersecurity.

Network security constantly evolves to meet the demands of an ever-changing working environment. Block malicious threats and restrict inappropriate user behaviours. The USG FLEX H series leverages AI-powered cloud intelligence to operate multi-layered protection such as sandboxing, anti-malware, DNS/IP/URL filtering, IPS, and application patrol over your premises.

Our new Fast and Powerful uOS.

The USG FLEX H series introduces our latest powerful uOS (Operating System). It is designed to increase security, minimize system response time, apply configuration changes instantly and optimize configuration and security policy management with its new intuitive UX (User Experience) design.

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Network Security



Hardware Specifications
Interface ports 2 x 2.5-GbE Ethernet
2 x 10-GbE/PoE Ethernet (802.3at, total 30W)
8 x 1-GbE Ethernet
2 x 10-GbE SFP+
USB 3.0 ports 1
Console port Yes (RJ45)
Rack-mountable Yes
Fanless -
System Capacity & Performance*1
SPI firewall throughput(Mbps)*2 15,000
VPN throughput (Mbps)*3 3,000
IPS throughput (Mbps)*4 6,300
Anti-Malware throughput (Mbps)*4 4,000
UTM throughput (Anti-Malware & IPS, Mbps)*4 4,000
Max. TCP concurrent sessions*5 2,000,000
Max. concurrent IPsec VPN tunnels*6 1,000
Recommended gateway-to-gateway IPsec VPN tunnels 300
Concurrent SSL VPN users 500
VLAN interface 128
Max. Concurrent devices logins*7 4,000
Security Service*8
Anti-Malware Yes
Application Patrol Yes
Web Filtering Yes
Reputation Filter Yes
SecuReporter Yes
Sandboxing Yes
Device Insight Yes
Secure WiFi*9 Yes
Key Features
SSL (HTTPS) inspection Yes
Two-Factor Authentication Yes
Nebula Centralized Management Yes
Power input 100-240V AC, 50/60Hz, 2A max.
Max. power consumption (watt) 86.7
Heat dissipation (BTU/hr) 235
PoE power budget (watt max.) 30
Physical Specifications
Item Dimensions (WxDxH)(mm/in.): 430 x 250 x 43.5/16.93 x 9.84 x 1.71
Weight (kg/lb.): 3.14/6.93
Packing Dimensions (WxDxH)(mm/in.): 512 x 395 x 162/20.16 x 15.55 x 6.38
Weight (kg/lb.): 4.90/10.81
Included accessories Power cord
RJ-45 - RS-232 cable for console connection
Rack mounting kit
Environmental Specifications
Operating Temperature: 0°C to 40°C / 32°F to 104°F
Humidity: 10% to 90% (non-condensing)
Storage Temperature: -30°C to 70°C / -22°F to 158°F
Humidity: 10% to 90%(non-condensing)
MTBF (hr) 40°C/ 431877.9743 hr
25°C/ 669031.2966 hr
Acoustic noise 16.85dBA on < 25degC Operating Temperature, 47.84dBA on full FAN speed
EMC FCC Part 15 (Class B)
CE EMC (Class B)
RCM (Class B)
Safety LVD (EN62368-1)


*: This matrix with firmware uOS1.10 or later.

*1: Actual performance may vary depending on system configuration,network conditions, and activated applications.

*2: Maximum throughput based on RFC 2544 (1,518-byte UDP packets).

*3: VPN throughput measurement are based on RFC 2544 (1,424-byte UDP packets); IMIX: UDP throughput based on a combination of 64 byte, 512 byte, and 1424 byte packet sizes.

*4: Anti-Malware (with Express Mode) and IPS throughput is measured using the industry standard HTTP performance test (1,460-byte HTTP packets). Testing done with multiple flows.

*5: Maximum sessions are measured using the industry standard IXIA IxLoad testing tool.

*6: Including Gateway-to-Gateway and Client-to-Gateway.

*7: This is the recommend maximum number of concurrent logged-in devices.

*8: With Zyxel service license to enable or extend the feature capacity.

*9: Available in Q2, 2024.

License Service

Gold Security Pack Other Licenses
Sandboxing Nebula Pro Pack
Reputation Filter* Nebula Plus Pack
Web Filtering
Application Patrol
Device Insight
Secure WiFi*1
Nebula Pro Pack

* USG FLEX H enhances Reputation Filter service with IP reputation included

*1: Available in Q2, 2024

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