EPOS | SENNHEISER GSX 300. Audio output channels: 7.1 channels, Audio quality: 24 bit, Recommended headphone impedance: 25 - 75 O. Host interface: USB, Headphone connectivity: 3.5 mm. Total Harmonic Distortion (THD): 0.01%, Cable length: 1.2 m, Product colour: Black. Package width: 169 mm, Package depth: 57 mm, Package height: 142 mm. Master (outer) case width: 310 mm, Master (outer) case length: 350 mm, Master (outer) case height: 310 mm