Fusion Flex J3i 3-drive mounting system for Mac Pro

$423.50 AUD AU

Item Code : SNT-FUS-FLEX-J3

RRP (ex GST): $385.00 AUD

RRP (inc GST): $423.50 AUD

Item Code : SNT-FUS-FLEX-J3

RRP (ex GST): $385.00 AUD

RRP (inc GST): $423.50 AUD


3-drive mounting system for Mac Pro (2023 or 2019)

Mount up to Three of your SATA Drives in Your Mac Pro

The Mac Pro® offers fast 3,400 MB/s internal SSD storage, capacity is limited to 8TB. Connecting external drives is an option, but why not just use the space and connections inside the Mac Pro to add capacity? Sonnet’s Fusion™ Flex J3i makes it easy, enabling you to securely install and connect up to three SATA drives (sold separately) in the available space next to the PCIe card slots.

Install Two 3.5-inch Drives Plus One 2.5-inch SSD Into Your 2023 or 2019 Mac Pro

Not only does the Fusion Flex J3i provide support for mounting two 3.5-inch hard drives of your choice, the Flex’s custom design provides mounting support for an additional 2.5-inch SATA SSD. Of course, the necessary mounting hardware and connecting cables are included for a clean installation.
Drives sold separately

Or Install Three 2.5-inch SSDs

The Fusion Flex J3i includes mounting plates and screws that enable you to install three 2.5-inch SSDs in total.
Drives sold separately

Fusion Flex J3i RAID O Performance

RAID your SSDs in the Fusion Flex J3i to achieve superior performance
Three 2.5″ SATA SSDs RAID O
Performance based on ATTO Disk Benchmark (available on the Apple® App Store ) test results with SanDisk® Ultra II 1TB SSDs with 8MB and greater transfer size. Two SSD RAID 0 tested with both SSDs connected to internal SATA ports. See our Performance PDF for additional benchmarks and details.

Custom Design, Rugged Construction

Sonnet designed the Fusion Flex J3i to make maximum use of the space and connections inside the Mac Pro; constructed out of heavy-gauge aluminum, the J3i looks right at home inside the computer. Shock and vibration isolators for 3.5-inch drives protects each drive from cross-coupled vibration from the other, safeguarding against read/write errors and retries. Mounting plates for 2.5-inch drives are included, so there’s no need to purchase separate pieces to use them. Custom power and data cables deliver a clean look to the installation.
View Fusion Flex J3i in Detail

Migration Assistant

The Fusion Flex J3i makes it easy to move two 3.5-inch hard drives from your 2010 or 2012 Mac Pro into your 2019 or 2023 Mac Pro, with no additional adapters or cables required.

Key Features

Add up to 52TB of Storage

Mounts up to three cost-effective SATA drives (sold separately) inside a Mac Pro. You get to choose the drives that suit your needs.

Mounts up to Three SATA Drives

Custom bracket and cables support one 2.5-inch SATA SSD plus two 3.5-inch SATA drives, or three 2.5-inch SATA SSDs.

Rugged & Custom Design

Vibration-absorbing isolators safeguard reliable disk operation whether in the studio or on the road; designed to make maximum use of the space and connections inside the Mac Pro.

Lifetime Tech Support

Sonnet was established in Irvine, California in 1986. Since then, we’ve pioneered and brought to market many innovative and award-winning products that enhance the performance and connectivity of Mac, Windows, and other industry-standard computers. Many of our employees have been with the company for more than 20 years. We have a wealth of knowledge about our current and past products. Should you ever need technical support on one of our products, contact us; we’ll be around to help you.

Product Specifications

Mac Compatibility

  • Mac Pro 14,8 (2023) Desktop and Rackmount
  • Mac Pro 7,1 (2019) Desktop and Rackmount

Boot Support

  • Mac Pro 2019 (Intel)
  • SSD connected to USB port bootable
  • SSD/HD connected to SATA port bootable(1)
  • Mac Pro 2023 (M2 Ultra)
  • SSD connected to USB port bootable(2)
  • SSD connected to SATA port n ot bootable


Part Number     FUS-FLEX-J3
Warranty           2-year
Form Factor     Expansion bracket
Dimensions     140 x 120 x 87 mm
Compliance.    RoHS 3 (Directive 2015/863)
IEC62368-1 and IEC62368-2 Safety

Package Contents

  • Fusion Flex J3i Expansion Bracket
  • 2.5-inch drive mounting bracket x2
  • 2-drive SATA data/power cable assembly
  • USB-3 to SATA data/power adapter cable
  • Vibration isolators and mounting screws

Support Links

Documentation and FAQs

Product Manual

Technical Notes

  • Booting from Mac Pro 2019 from SATA port requires Security Setting change to enable external boot because macOS treats Mac Pro 2019 SATA ports as external.
  • To create a boot volume for Mac Pro 2023: a) install SSD in Fusion Flex J3i and connect to internal USB 3 port; then b) format SSD and install macOS.

Additional information

MPN : FUS-FLEX-J3Brand : SonnetWeight(Kg) : 1.5 Platform : Mac
Weight 1.5 kg
Dimensions 14 × 12 × 8.7 cm