Millenium HPA In Ear - compact headphone preamp made for In Ear systems, stereo XLR or 1/4" jack input, mini-jack headphone out, mono/stereo/mix mode switch, volume and balance/mix control, workds with power supply (including) or optional 9V Battery (132579). Stand or claw mount (3/8" thread on the side). Dimensions: 170 x 95 x 45mm. Weight: 450g, 9V battery optional available