OMNITRONIC LH-031 is a four-channel headphone distribution amplifier that routes one stereo audio source to four independently controllable headphone outputs. The unit provides RCA, 3.5 mm jack, and 6.3 mm jack stereo inputs, switchable to mono, and four 6.3 mm headphone outputs. It has a 20 Hz–20 kHz frequency range, greater than 90 dB signal-to-noise ratio, less than 0.008% THD at 1 kHz, 20 dB gain, and a silver housing measuring 11.3 × 8.5 × 5.5 cm.