Objective2 Headphone Amplifier By MER LV Labs Frequency Response: 20Hz-20kHz +/- 0.01 dB Maximum THD: 0.0023% Gain: 2.5x and 6.5x Case Dimensions: 4.3" wide x 3.15" long x 1.18" high (not including buttons or knobs) Weight: 10.3 ounces