Mackie Big Knob Studio, Active Monitor Controller, for up to 2 monitor pairs and 3 stereo sources, 2x2 USB audio interface 24 bit / 192 kHz, Large volume control, Switches for mute, dim, mono, monitor and signal source, Independent trim for all sources and monitor outputs, Cue mix function, Integrated talkback microphone, 16-segment LED metering, +48 V phantom power, Steel housing, iOS support with optional Lightning to USB 3.0 camera adapter for connection to iPad and iPhone (adapter not included), For Mac and PC, Includes Tracktion waveform recording software@+*Connections:*@+@+, 2 Microphone/line XLR/jack 6.3 mm combo inputs, 2 Line inputs 6.3 mm jack balanced, 2 Track connections 6.3 mm jack (L/R), 2 Stereo monitor outputs 6.3 mm jack, 2 Stereo headphone outputs 6.3 mm jack, 1 Stereo line input 3.5 mm mini jack, USB, Power supply connection