API Audio MC531 Monitor Controller, Active Monitor Controller, For connection of up to 3 monitor pairs, Integrated talkback microphone, Mute, mono and DIM function for all stereo outputs, 18 Segment LED meter, Bluetooth connectivity, API 2510 operational amplifier for all inputs, 3 Stereo line inputs: 6x jack 6.3 mm balanced, 2 Line inputs: 3.5 mm mini-jack stereo (front and rear), Digital input switchable between AES3 XLR and USB, 3 Stereo line outputs: 6x XLR balanced, 1 Line output for subwoofer: XLR mono, 2 Stereo headphone outputs: 6.3 mm jack, Balanced level meter output for connection to an external meter system, Dimensions (W x D x H): 27.94 x 32.39 x 10.16 cm, Weight: approx. 3.86 kg, Incl. external power supply unit