The Viper SSC (eSATA and USB model) suits the very basic need of external storage users. Fabricated in rigid aluminum, The Viper SSC possesses a metal tray internally to stabilize and protect HDD and also to quicken the time it takes to install a hard drive. The Viper SSC equipped with USB 2.0 and eSATA combo interface offers data transfer speeds up to 3G/sec. The Viper SSC works with a PC or a Mac and is designed to be a lightweight and compact portable storage device. The Viper SSC occupies no space by utilizing the vertical stand included with every unit. Powered by the 12V2A adapter, it supports almost all 3.5" SATA HDD up to date instantly adding storage to desktops or notebooks. Notice Enable Hot-Swap Function: In order to enable HOT-SWAP function, please check to make sure the motherboard supports HOT-SWAP function. Otherwise, the hot swappable function will not work. (Please refer back to motherboard user guide)