Physical Features:

While not the smallest external hard drive in Transcend's product lineup, the StoreJet 25D3 is still fairly compact and lightweight. Sharing the same basic design as the 25D2, Transcend's new drive measures 129.9 × 82.1 × 17.3 mm and weighs in at 191g. The StoreJet 25D3's case is constructed out of lightweight, black plastic. While the top of the drive has what Transcend calls a "gloss piano finish," the bottom and sides have more of a matte finish.

Along the back, you can see the drive's SuperSpeed USB 3.0 interface and power connector. The StoreJet 25D3 can be powered off a computer's USB bus. However, if your computer cannot provide the 5V DC required by the drive, you'll need to use the included USB power cable.

On top of the StoreJet 25D3 there is a multicolor LED which lights up orange or blue, depending on the USB connection type. This indicator light also flashes to show when data is being transferred. 

Inside the case, you'll find Transcend's shock-dampening system which incorporates internal suspension technology to protect the hard drive from damage caused by accidental slips or falls.

I wasn't able to crack the StoreJet 25D3 open. However, using CrystalDiskInfo, I was able to see what hard drive was in the enclosure. Looking at the screenshot below, you can see that Transcend has used Samsung's Spinpoint M7E  (HM501II) hard drive. This drive features a SATA 3.0Gb/s interface, 8MB cache and a 5400 RPM rotation speed.