Computer Accessory Sets features: 5.1 Channel Optical USB Sound audio controller Color: we send based on the color or size of the main image of the product page. Quantity：we send based on quantity on title, if there is no quantity in the title, we send based on description. 1) Supports AES/EBU,IEC60958,S/PDIF consumer formats for stereo PCM audio 2) Fixed 48KHz sampling rate for 5.1 channel playback 3) Supports digital recording function with 32khz, 44khz and 48khz sampling rates 4) Supports analog recording function 5) Supports SCMS (Serial Copy Management System) copy protection 6) Compatible with Win98SE,ME,2000,XP,Mac OS 9.1 (Mac version has 2 channel playback only) 7) Fully duplex playback/recording audio stream without sound card in PC 8) Compliant with USB specification v1.1 9) Compliant with USB audio device class v1.0 10) Supports USB full speed 12Mbit serial data transmission 11) 3 input terminals 12) 3 output terminals 13) Alternate setting 0 is a zero bandwidth setting used to release the claimed bandwidth on the bus when this device is inactive 14) Isochronous transfer uses adaptive and asynchronous synchronization 15) Supports multi channels audio code interface for 5.1 channel playback 16) Supports conventional audio 2 channels source playback (only L, R, channel active) 17) Plug and Play under windows without external memory