Close on the heels of Toshiba’s recently unveiling of a 9mm-thick 500GB external hard drive, ADATA has introduced an 8.9mm-thick portable, stainless steel USB 3.0 external hard drive, which will apparently be the “world’s thinnest” drive of its kind.

The new drive announced by ADATA is called the DashDrive Elite HE720, and it is slightly more than one-third of an inch in thickness. Along with being thinner than Toshiba’s newly-unveiled drive, the $90-priced ADATA drive is also $25 cheaper than the Toshiba drive.

Boasting a simple brushed stainless steel exterior, the ADATA DashDrive Elite HE720 sports a blue LED and an ADATA symbol. The metallic exterior of the drive is quite immune to scratches even in the long run, largely because it is covered by a thin protective layer that has a 9H hardness rating.

Underscoring a notable combination of aesthetics and functionality, the ADATA DashDrive Elite HE720 is capable of super-fast USB 3.0 transfer speeds, and also includes a “one-touch backup” feature.

Scheduled to hit the markets soon, the DashDrive Elite HE720 from ADATA – to be available at Amazon, Newegg, and Tiger Direct - will come with a three-year warranty; and a 60-day trial to Norton Internet Security 2012.