1. This is a special HIFI expansion board designed for the for B+ , using TI's chip (PCM5122), using an I2S interface. 2. The user can use this expansion board with audio playback systems (for volumio, for xbmc system etc.) to build its own network HIFI player. 3. The expansion board provides two kinds of output interfaces to facilitate external amplifiers and other equipment. 4. It provides LED indicates working status. Red LED for the power indicator (Power normal light), the green LED for the working condition (when working decode light, stop, or does not work when off), a better understanding of the work of the provide infrared receiver interface (occupied GPIO26). Sampling Frequency: 384KHz Resolution (Bits): 16-32 Digital Audio Interface: I2S : 120dB : -93dB Dynamic range: 112dB Supports for B+, for 2 Model B Colour:Black Material:plastic Package Contents: 1 x Audio Sound Card Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.