Four 1/4 unbalanced line-level inputs with individual volume controls mixed to one 1/4 unbalanced output; Master volume control with integrated power on/off switch & power on LED indicator; Ultralow distortion, up to 20dB of gain, signal-to-noise ratio over 100dB; Freq resp: 20Hz-20kHz; Heavy-duty steel construction with smooth-turn, ultrastable pots & high-quality jacks; 9V DC powered with either 9V alkaline battery or optional PAD-1 AC/DC external adapter; Dim: 5.8H x 4.3W x 2.1D;