Western Digital has launched a new Thunderbolt RAID-capable external drive called the My Book Pro:

The My Book Pro connects a pair of 3, 4, 5, or 6TB HDD's to a host system via either 20 Gbps Thunderbolt or USB 3.0 (at 5 Gbps). The unit comes preconfigured as a RAID-0 to give full capacities of 6, 8, 10, or 12 TB, but can be switched to RAID-1 or JBOD mode upon connection to a host system. Note that RAID-1 (mirroring) will cut the usable capacity in half – limiting to the capacity of a single drive. As seen above, there are also a pair of USB 3.0 ports at the front of the unit for connecting additional devices to the host via the My Book Pro.

Looking at the rear, we see a pair of Thunderbolt ports (daisy chaining of up to six My Book Pros is supported), as well as a USB 3.0 port.

We are not sure which drives come pre-installed, but the press release clearly states 7200 RPM and since WD just launched a higher capacities of the Red Pro, we'd guess that was their choice here.

Press blast appears after the break.

FOR IMMEDIATE RELEASE:

NEW MY BOOK PRO IS WD’S FASTEST EXTERNAL SOLUTION 
 
New Thunderbolt Drive Offers up to 12 TB of Storage for Professional Content Creators 

IRVINE, Calif. and BERLIN – Sept. 2, 2015 – WD®, a Western Digital (NASDAQ: WDC) company, today introduced the My Book® Pro storage device, providing professionals and enthusiasts who must efficiently manage large amounts of digital content with up to 435 MB/s transfer rates on WD’s fastest external storage solution yet.  
     With capacity options including 6 TB, 8 TB, 10 TB and 12 TB , the power of two 7200 RPM WD drives with Intel’s Thunderbolt™ 2 technology and a hot-swappable hardware RAID controller, the My Book Pro device enables creative professionals and enthusiasts alike to focus on what they love doing by significantly cutting the time to transfer large videos, photos and audio files. 
     “The My Book Pro device has been designed from the ground up for the creative professional workflow.  We’ve been able to take the newest, highest capacity 6 TB 7200 RPM drives on the market and marry them with leading technologies to deliver a product you can leverage from the moment you connect it.” said Sven Rathjen, vice president of marketing for WD’s Content Solutions business. “It really is designed to perform under the most demanding environments.”  
     Designed for professional content creators who need performance and capacity, My Book Pro storage combines the power of dual 20 Gb/s Thunderbolt 2 ports, USB 3.0 compatibility, the peace-of-mind of hardware RAID and the speed of two 7200 RPM WD drives to accelerate creative workflows. With the convenience of two front-access USB ports and the ability to daisy chain up to six Thunderbolt devices, users are able to charge and sync smartphones, tablets or cameras while simultaneously connecting 4K monitors or additional storage devices. 
     At any point in time, one’s data could be at risk if not protected. Whether it’s a lost notebook or destructive virus, it’s critical to keep data safe and maintain a backup of important documents and valued content. With three customizable configuration options [RAID 0 (default), RAID 1 and JBOD] offered by the My Book Pro device for keeping content protected, data bottlenecks are reduced and throughput is improved with no impact to your computer’s CPU performance.
Pricing and Availability
     The My Book Pro storage device is protected by a 3-year limited warranty and is available from the WD store at wdstore.com as well as select retailers and distributors. Manufacturer’s suggested retail price (MSRP) will be $599.00 USD for the 6 TB, $749.00 for the 8 TB, $899.00 for the 10 TB and $999.00 for the 12 TB.