Internal READ ONLY UDD25

This internal READ ONLY UDD25 is a READ only device that blocks any WRITE commands. This READER supports READ only function for storage media such as 2.5" or 1.8" HDD / SSD, M2 card, mSATA SSD, CFast card and CF card. The WRITE PROTECT feature of this READER ensures absolute protection to the storage media from virus contamination or data tampering.  It is a great tool for sharing drives containing important data among different users or for forensic application. This READER essentially treats any hard drive or SSD as a READ only media, similar to the CD or DVD disc.

The storage media can be inserted or removed from the READER like a floppy disc without restarting the system. Pratically any storage media that is the same size as the 2.5" hard drive and with the same SATA connector can be accessed by this Internal READ ONLY UDD25.  Designed to mount directly into a standard 3.5" drive bay, the internal UDD25 connects to a Desktop, Server or computing equipment via the ubiquitous USB 3.0 / 2.0 port.

For the same READER with full READ/WRITE function, please visit the Internal UDD25 product page.

Features illustration of Internal READ ONLY UDD25


The following Addonics optional 2.5" flash drive kit can READ M2, mSATA, CFast or CF cards via the Internal READ ONLY UDD25:

Show with media side facing up 

M2 card in 2.5" M2 drive
kit (AD25M2SSD-E)

mSATA SSD in 2.5" mSATA
drive kit (AD25MSD-E)

CFast card in 2.5" CFast 
drive kit (AD25CFASTD-N)

CF card in 2.5" CF drive kit

Slim SATA SSD 2.5" HDD
adapter (AA25SEMBK)

1.8" micro SATA - 2.5" SATA
HDD adapter (AD18M25S

note: the flash cards shown above are for illustration purpose and are not part of the 2.5" flash drive adapter.

  • READ only device
  • Protect drive against virus contamination or data tempering
  • WRITE disabled at hardware level. No software hacking to circumvent the WRITE PROTECT function
  • No volatile memory
  • Drive appears to OS as READ only device. Options to format, delete and other commands that alter the content, partition table or MBR of the drive are all disabled by the OS (see screen shots from Windows OS below)
  • READ standard 2.5" SATA HDD/SSD or storage media with same dimension and connectors of the standard 2.5" SATA HDD 
  • Read M2, mSATA, CFast and CF card using optional Addonics 2.5" flash drive kit (these adapters are included in the PRO model: UDD25U3WP-4F)
  • Read 1.8" micro SATA hard drive or SSD with optional 1.8" adapter (AD18M25S
  • Media can be insert or removed like using a floppy disc without restarting the computer
  • Supported drive height from 7 - 9.5 mm
  • Mount into any standard 3.5" drive bay or 5 1/4" drive bay with optional mounting bracket (AAMK53)
  • Connect to system via USB 3.0 /2.0 port
  • Support USB 3.0 and 2.0 speed*, up to 5 Gbps data transfer* with USB 3.0 connection
  • Comes with all necessary cables:
    • USB 3.0 male A to internal USB 3.0 header cable (AAU3AHM)
    • USB 2.0 male to USB 5-pin male header cable (AAUSB51M)
    • USB 2.0 pin header cable (AA5PUSBCL-3F)
  • Power from USB port, or PC power supply
  • Complete Plug and Play, no software driver to install
  • Media can be used as a boot device (for CF card, it may need to be fixed disk type depending on the OS)
  • Compatible with Windows 8, 7, Me, XP, 98SE, all versions of Windows Server, Mac 9.0 and later release, Linux kernel 2.4 and later


*Note: Maximum data transfer rate depends on the speed of the storage media


Sample of Windows 8 screen shots showing options to format, delete and other commands that alter the content or structure of the drive are all diabled by the OS 


  • Drive slot accommodates drive thickness up to 9.5 mm
  • Device interface connectors: USB 3.0 type A female
  • Combo LED for power and drive access
  • Powered from USB port or via a small 4P Molex power connector
  • Dimension (W x L x H): 101 x 127 x 25 mm (3.98 x 5 x .98 in.)
  • Weight: 200 g (7.05 oz.)
  • Operating temperature and humidity: 0 - 65° C, 5 - 90 %RH
  • Storage temperature and humidity: -20 - 75 ° C, 0 - 95 %RH (non-condensing)


UDD25U3WP - (Internal READ ONLY UDD25, USB 3.0)
Content: Internal READ ONLY UDD25 with USB 3.0 connection, 24" USB 3.0 male A - USB 3.0 header cable (AAU3AMH), 18" USB 2.0 A male - 5-pin header male cable (AAUSB51M), 1M USB 2.0 female pin header cable (AA5PUSBCL-3F), user guide.
Price: 49.00
UDD25U3WP-4F - (Internal READ ONLY UDD25 PRO, USB 3.0)
Content: Internal READ ONLY UDD25 with USB 3.0 connection, 24" USB 3.0 male A - USB 3.0 header cable (AAU3AMH), 18" USB 2.0 A male - 5-pin header male cable (AAUSB51M), 1M USB 2.0 female pin header cable (AA5PUSBCL-3F), 2.5" M2 Flash drive (AD25M2SSD), 2.5" mSATA flash drive (AD25MSD), 2.5" CFast flash drive (AD25CFASTD-N), 2.5" CF flash drive (AD25CFD-N), user guide.
Price: 119.00


AAU3AMH (USB 3.0 male A - header male cable, 18")
Content: 18" USB 3.0 type A male to USB 3.0 header cable
Price: 8.99
AA5PUSBCL-3F (3' USB cbl, female pin header both ends)
AA5PUSBCL-3F USB 5-pin header to 5-pin header 3 feet cable. Suitable for connecting any device with USB 5-pin header connector to 5-pin header connector on system board.
Price: 1.99
AAUSB51M (USB adapter cable to standard USB port)
AAUSB51M connecting cable for Internal USB 2.0 DigiDrive , AEIDMDU2 or AEIDMDU2B, to standard USB output connector.
Price: 2.00
AD18M25S (1.8" micro SATA - 2.5" SATA HDD adapter)
Content: 1.8" micro SATA - 2.5" SATA HDD adapter,
Price: 19.00
AD25M2SSD-E (2.5" M2 Flash drive kit PRO)
Content: 2.5" M2 (NGFF) SSD drive kit with easy media installation or removal design
Price: 24.95
AD25MSD-E (2.5" mSATA flash hard drive kit PRO)
Content: 2.5" mSATA flash memory hard drive kit for standard mSATA and mSATA mini (half size) SSD
Price: 24.95
AD25CFASTD-N (2.5" CFast HDD kit, open end, black )
Content: 2.5" CFast hard drive kit with open end black color bracket for easy media nstallation, user guide.
Price: 24.95
AD25CFD-N (2.5" CF HDD PRO, easy media insertion and removal, black color)
Content: 2.5" CF hard drive kit with a half open-end black color bracket for easy media installation.
Price: 26.95
AA25SEMBK (Slim SATA SSD 2.5" HDD adapter)
Content: 2.5" HDD adapter kit for slim SATA embedded SSD, user guiode
Price: 19.00