ZALMAN ZM-RSSC is an external 5.1 channel USB sound card that can be used with PCs without a sound card, PCs with only a stereo sound card, and notebook computers in which a multi-channel sound card cannot be installed. It supports both optical and coaxial types of digital outputs along with analog 5.1 channel outputs, and it comes with three volume controls for independent level adjustments for the Front, Rear, and Center/Subwoofer output channels. The sound card is easy to connect with its plug-and-play USB interface, and it includes an amplifier for full sound and ease of use.