USB 3.0 WriteBlocker
Fast forensic access to USB 3.0 storage devices


Digital forensics investigators, lawyers, and corporate IT staff who want to view, examine, and image drives quickly and easily, look to the CRU® WiebeTech® USB 3.0 WriteBlocker™ to ensure they are protecting and not altering data.

The handheld and lightweight USB 3.0 WriteBlocker connects via a Windows operating system host's USB 3 interface to allow investigators and technicians to look through the contents of a drive without risking any damage or disruption of source data. To use, simply use the included USB 3.0 cable to connect the USB 3.0 WriteBlocker to the drive or drives you wish to inspect.

Additional features:

  • Bus powered
  • Status LED indicates if drive is safe to inspect
  • Industry-leading 3-year warranty
  • Free, US-based customer support

The WiebeTech WriteBlocking Validation Utility, our complimentary Windows application, tests the reliability of any write blocker available, hardware or software.

Included Items

  • AC adapter
  • USB 3.0 cable (type A to B)
  • Quick start guide
  • USB thumb drive containing drivers and related files

Specs at a glance Full Product Specs >

Drive Types Supported
  • USB Thumb Drives
  • USB drives via USB cable (if the device class is USB Mass Storage Device and it does not use proprietary firmware)
Dimensions 3.43" x 2.05" x 1.02" (87mm x 52mm x 26mm)

Part Numbers

USB 3.0 WriteBlocker

Read-only access to 2 USB 3.0 storage devices at the same time; bus-powerable

US plug
part #: 31350-1279-0000
Ships in: 1-2 Days

US, UK, EU, & Aus plugs
part #: 31359-1279-0000
Ships in: 1-2 Days


Product name USB 3.0 WriteBlocker
Patent Patent Pending
Host (I/O) Ports (1) USB 3.0: up to 5 Gbps
Drive Types Supported
  • USB Thumb Drives
  • USB drives via USB cable (if the device class is USB Mass Storage Device and it does not use proprietary firmware)
Number of LEDs 1
Description of LEDs Power/Authentication status
Operating system compatibility Windows 7, 8, or 10 (note: virtual machines not supported)
Construction material(s) ABS
Power input connector Barrel connector (center pin positive)
Bus power Yes (one port)
Dimensions 3.43" x 2.05" x 1.02" (87mm x 52mm x 26mm)
Weight 0.13 lbs. (0.06 kg)
Write Blocking Yes
Write Blocked ports Dual USB 3.0
Compliancy FCC, CE, RoHS, RCM
Warranty CRU provides a 3-year limited warranty for this product.
Technical Support Your investment in CRU products is backed up by our free technical support for the lifetime of the product. If you need to contact us for any reason, visit or call us at 1-800-260-9800 or +1-360-816-1800.

Product Images


May 23, 2016 - 14.07 MB
WiebeTech WriteBlocking Validation Utility 64-bit Windows
May 23, 2016 - 12.82 MB
WiebeTech WriteBlocking Validation Utility 32-bit Windows
May 10, 2017 - 1.5 MB
Windows Drivers for USB 3.0 WriteBlocker (32-bit and 64-bit)
May 16, 2017 - 490.38 KB
Quick Start Guide for USB 3.0 WriteBlocker


Q : Is USB 3.0 WriteBlocker compatible with Western Digital PassPort brand USB3 drives?

WD PassPort drives include an auto-launching software app called "Smartware" which allows its user to reformat, set up encryption, etc. Most forensic write-blockers will not work with such drives, but USB 3.0 WriteBlocker will as long as you have installed USB 3.0 WriteBlocker driver version 1.0.3 or newer.

The latest software driver is always available for download from the product page's "Resources and Documents" tab.

Q : Does USB 3.0 WriteBlocker work with UASP drives? What about composite or compound drives?

With driver version 1.0.3 (or newer), USB 3.0 WriteBlocker can now writeblock USB drives that use UASP (USB Attached SCSI Protocol) as well as Composite USB devices, a device type commonly used for external hard drive enclosures such as WD’s MyBook.

The latest software driver is always available for download from the product page's "Resources and Documents" tab.

Q : Are there any types of USB drives I should avoid using with USB 3.0 WriteBlocker?

Drives that require a third-party driver to be installed should not be used with the USB 3.0 WriteBlocker. The USB 3.0 WriteBlocker is designed to operate with devices that use the generic USB and disk drivers that come packaged with Windows. Devices that do not use the generic Windows drivers cannot be guaranteed to operate correctly with the USB 3.0 WriteBlocker.

Q : Can this product operate without installing drivers?

USB 3.0 WriteBlocker requires installation of a custom driver file. The installer app for the driver can be found on the USB thumb drive that shipped with the product, or on the "Resources and Documents" tab on the product's webpage. We recommend downloading the latest driver for best performance.

Q : Why am I asked to update my driver during installation?

Driver updates are released occasionally to improve performance and compatibility of your USB 3.0 WriteBlocker. We recommend periodically checking for new versions of the driver to make sure it is up to date.

Updates can be found on the CRU USB 3.0 WriteBlocker product page:

Q : The message "CRU USB 3.0 WriteBlocker could not be installed because a critical system update is missing" appears after launching the installer. Why can't I install the driver?

Windows Security Update KB3033929 is an update that allows your computer to verify the publisher of files and drivers. This update must be installed for the CRU USB 3.0 WriteBlocker driver to function. Computers using Windows 7 are required to install this update. No action is needed for Windows 8, 10, and later.

The update can be downloaded directly from Microsoft:

After downloading the appropriate file for your system, open it and proceed with the installation. When prompted, reboot the computer. You can now install the CRU USB 3.0 WriteBlocker driver.

More details about this security update can be found here:

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