4-Port High Security Dual-Head DVI KVM Multiviewer/Combiner



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The K424F-SH is a secure KVM (Keyboard, Video and Mouse) multiviewer (combiner) that provides secure isolation between connected computers while enabling smooth KVM operation and switching. Maintaining the separation of computers connected to a KVM switch is critical, particularly when the computers have differing levels of security, clearance and Internet access. The K424-SH allows for the user to monitor all four computers at once on one or two monitors by scaling each source in real time with no latency or loss of picture quality. Users can quickly and effortlessly rescale the windows to fit their viewing needs.

Other secure KVM devices on the market today only allow for users to view one computer at a time. The K424-SH is the only secure KVM combiner of its kind for when users require the secure management of four channels simultaneously, with seamless switching between KVM operation on any connected computer.

Smart Security Labs is a partnership between SmartAVI and High Sec Labs

The unmatched isolation and security delivered by the K424-SH is critical in government, defense and other high-security venues. Furthermore, the unit is fully compatible with legacy and new government systems. The K424-SH has been certified to meet EAL 4+ standards to assure it provides the highest level of security possible. In part, the unit achieves this ultimate level of security because it was programmed with the assumption that two of the connected computers are infected by a hostile code that's constantly trying to attack the KVM. The result is the most secure KVM solution on the market today.

The security protections built into the K424F-SH ensure the unit cannot be compromised by any known KVM attacks. Unidirectional optical data diodes allow data to flow only from devices to the host, and never in reverse for enhanced isolation. With no dependence on firmware or software, this KVM unit keeps connected computers safe. After manufacturing, an anti-tampering system is activated and each unit is provided with a special holographic tampering-evident label to ensure the device has not been tampered with.

User-Friendly Window Rescaling

Pictured here is the K424-SH KVM multiviewer (combiner) in Cascade Mode (left side) and in Tile Mode (right side). The K424- SH gives users the option to layout a single screen as seen here, or to add a second screen to further enhance the visual layout possibilities, enabling users to monitor and manage all the connected computers exactly how they want to with just a click of the mouse.

Why choose the K424F-SH?
KVM connections have become a target for cyber attacks as they may be the only possible link to bridge between isolated classified networks and networks open to the Internet. Many high security organizations are adopting secure KVM devices as part of their cyber protection strategy, but other secure KVM units sold on the market today have documented vulnerabilities that may cause data leakages between connected computers with different security levels.

The production in the K300, K400 and K500 series are the only third-generation secure KVM devices available today. This product offers the highest possible separation between four connected computers. The K424F-SH has been meticulously designed and rigorously tested to meet the requirements of organizations that are challenged by the need to provide secret or top-secret network access together with unclassified or Internet access. Each K424-SH manufactured has passed an extensive security evaluation through all forms of known KVM attacks.

The K424F-SH is an essential tool for users challenged by frequent switching between isolated networks. The combination of up to four isolated sources into one or two combined display improves the usability and situational awareness. This product resolves challenges of virtualization while adding additional security protections. The RDC (Remote Desktop Controller) port enables simple interface with the RDC controller. Using the K424F-SH with RDC users, can control and monitor KVM functions remotely and securely.


  • Validated to EAL 4+ security standards
  • Complies with Common Criteria Protection Profile 2.1
  • View up to four isolated networks simultaneously and securely
  • Advanced scaling enables no quality loss
  • Supports two DVI displays
  • User-friendly window rescaling
  • Unidirectional data paths
  • No software or firmware required
  • Dedicated processors for emulation
  • USB port protection


  • Government Operations
  • Defense Applications
  • Security Control Rooms
  • Corporate Communications and Server Operations
  • Medical Campuses
  • Airports

Front and Back of the K424F-SH  KVM

SmartAVI K424F-SH Specifications
Host Computer Input Ports4 isolated ports to connect computers, each with: DVI-D Female connectors for video;
4 x USB Type-B connectors for keyboard and mouse;
4 x USB Type-B connectors for user authentication device
DVI-D supports DVI or HDMI sources only.
VGA can be supported using VGA to DVI Smart-Cable accessory (sold separately)
Galvanic ports isolation through optical data diodes and isolated power supplies
Plug and Play EDID support - four channels identified as standard displays
Console Ports2 USB Type-A jacks for keyboard, mouse;
PS/2 legacy keyboard connector (MiniDIN-5);
DVI-D display jack for user display;
3.5 mm stereo jack for amplified speakers or headset;
Remote Desktop Controller (RDC) port
ManagementChannel select/status LEDs, channel select push-buttons, keyboard hotkeys (optional - can be disabled)
Video Modes Supported800 x 600 (4:3) SVGA - 1280 x 1024 (5:4) SXGA - 1920 x 1080 (16:9) HD1080 - 1920 x 1200 (16:10) WUXGA
Output Video Modes Supported024 x 800 (16:10) WXGA - 1280 x 1024 (5:4) SXGA - 1600 x 1200 (4:3) UXGA - 1680 x 1050 (16:10) WSXGA+ 1920 x 1080 (16:9) HD1080 - 1920 x 1200 (16:10) WUXGA - Dual-link displays support [Future]
Security FunctionsUSB ports supporting only keyboard and mouse through host emulation and strong filtering.
Optical Data Diode assures unidirectional flow from devices to computers.
Firmware change can not cause leakage between channels or data export.
Isolated power supplies for each device emulator.
Dedicated port for smart-card reader or biometric device. Port is strongly filtered and monitored.
Firmware resides on ROM.
Battery powered anti-tampering system to disable product in case of mechanical intrusion.
Special holographic Temper Evident Labels.
Peripheral SecuritySB ports supporting only keyboard and mouse through host emulation
Data-diode assures USB unidirectional flow from devices to host
Firmware change can not cause leakage between channels or data export
Security AccreditationsCommon Criteria EAL 4+ ALC_FLR.3 certified
Complies with latest NIAP Peripheral Sharing Switch (PSS) For Human Interface Devices Ver 2.1
Products are NIAP CPL listed
PowerDC input 12V / 5A maximum
Brick power supply included. Power input 90-240V AC
EnvironmentalTemperature range: Operating - 0°C to 40°C (32°F to 104°F); Storage - -20°C to 60°C (-4°F to 140°F)
Humidity: Operating - 20 to 80% non condensing; Storage - 10 to 90% non condensing
Altitude: 0 to 10,000 ft
Physical CharacteristicsDimensions: 135(D) x 320(W) x 75(H) mm / 5.3(D) x 12.6(W) x 3.0(H) inch
Device weight: 1.8 Kg. (4.0 lbs.)
Shipping Weight: 2.2 Kg (4.8 lbs) without cables