Sonifex Redbox RB-UL2, Dual 2 channel balancer, Change from unbalanced to balanced, Trimmer level adjustable from -15 dBu to +15 dBu, 4 RCA inputs: unbalanced, 4 XLR outputs: balanced, Frequency range: 20 - 20,000 Hz, Dimensions (WxDxH): 28 x 10.8 x 4.2 cm, Weight: 1.05 kg