The NIO™-4×4 Mic/Line Input/Output Card is a four-channel mic/line level input and four-channel line level output device for use in NION® DSP frames. Modular analog audio input/output card and analog-to-digital and digital-to-analog converter for the NION Series of digital audio processing products. Depending on the NION model, up to four NIO-4×4 cards may be loaded in a NION DSP.