Rolls PM 55P Personal Monitor Amp, Personal Monitor Amp, Switchable stereo/mono monitor input, Switchable limiter, XLR Microphone input and output, Phantom power, Ground lift, 6.3 mm and 3.5 mm headphone jacks, Independent monitor level and microphone controls (line signal 6.3 mm jack balanced), 9 V Battery operation and power supply operation, Dimensions: 114 x 102 x 35 mm, Weight: 450 g, Includes power supply