USB WriteBlocker

    • Convenient USB write blocking
    • Reliable evidence protection
    • Simple, bus-powered operation
The USB WriteBlocker™ is a professional forensic tool for investigating USB mass storage devices, such as thumb drives. It is relied on by digital investigators, technicians, and IT staff.

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Technical Specs

Product name USB WriteBlocker
Host (I/O) Ports (1) USB 2.0: up to 480 Mbps
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)
Maximum HDD size 2000 GB (1000 GB in a Terabyte)
Number of LEDs 1
Description of LEDs Power, drive access
Operating system compatibility Windows XP or later
Windows Server 2003 or later
Mac OS X
Most modern Linux distributions
Construction material(s) ABS
Bus power Yes
Dimensions 4.13" x 1.02" x 0.63" (105mm x 26mm x 16mm)
Weight 0.10 lbs. (0.05 kg)
Write Blocking Yes
Compliancy FCC, CE, RoHS, C-Tick, RCM
Warranty CRU provides a 2-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.
Resources and Documents

Product Description

Lawyers, forensics investigators, and corporate IT staff who want to view and image USB mass storage devices, such as thumb drives, rely upon the CRU® WiebeTech® USB WriteBlocker™ to protect data.

The compact, highly portable USB WriteBlocker connects to USB storage devices and protects their contents during an investigation. To use, simply connect the WriteBlocker to the suspect device.

The USB WriteBlocker is compatible with USB 2.0 thumb drives and other USB mass storage class devices.  It will also work with some USB 3.0 devices at USB 2.0 speed. 

The USB WriteBlocker operates from bus power so you don't need to carry around a heavy power adapter.  Bus power is generally sufficient for use with USB thumb drives or self-powered drive enclosures.  An optional bus power boosting cable is available for use with bus-powered pocket drives that need extra power. 

Use the included Forensic Software Utility to display information about connected devices and enable you to save the information in common text formats.  You can download the utility from the "Resources and Documents" tab on this webpage.

Additional features:

  • Compact design
  • Plug-and-use operation
  • Free US-based customer support

Whether you're a corporate IT manager, forensic investigator, or lawyer, the USB WriteBlocker is a valuable part of your investigation toolkit. Find a reseller near you or buy online.

Included Items

  • USB extension cable (type A male to A female)
  • Removable lanyard
  • Rubber port shield
  • Quick start guide


Related Products


Products and Accessories

USB WriteBlocker
Inline USB pass-through device; blocks writes to attached USB mass storage devices; bus-powered
Black; w/cable & lanyard
part #: 31300-0192-0000
Ships in: 1-2 Days


USB Power Cable for USBWB
Accessory for USB WriteBlocker; allows bus-powerable USB drives to be used with USBWB without AC adapter
part #: 30080-0100-0000
Ships in: 1-2 Days