Specifications Audio circuit type: Passive, transformer based Transformer: Jensen JT-DBE Number of channels: Single channel (mono) Frequency response: 20Hz ~ 20KHz ( 0.2dB) Dynamic range: 135dB Total harmonic distortion: 0.05% from 20Hz ~ 20kHz @-10dB Phase Deviation: 0.3 @ 100Hz; 3 @ 20Hz Input Impedance: 140k Ohms, unbalanced Output Impedance: 150 Ohms, balanced Maximum Input: +21dB @ 20Hz ~ 20kHz Features Input pad, Mono Sum, 180 polarity reverse, Ground lift, Speaker filter General Construction: 14 gauge steel chassis & outer shell Finish: Durable powder coat Size (L x W x D): 5" x 3.3" x 1.8" (127mm x 84.1mm x 45.5mm) Weight: 1.55 lbs (703 grams) Shipping size (L x W x D): 6.5" x 4" x 3" (165mm x 102mm x 76mm) Shipping weight: 1.92 lbs (870.9 grams) Power: Passive, no power required Conditions: For use in dry locations only between 5C and 40C