Polycom Vortex EF2241. Input impedance: 10000 Ом, Analog input gain: 0 - 30 dB, Maximum input amplitude: +19 dB. Output gain: -100 - 20 dB, Maximum output amplitude: +23 dB, Output impedance: 33 Ом. Telephone input gain: -100 - 20 dB, Nominal transmit level: 0 dB, Off hook loop current: 16 - 120 mA. Signal-to-Noise Ratio (SNR): 90 dB, Output power: 8 Ohm, >10W, 20-20000 Hz, + 0.2/- 0.5 dB, Impedance: 16 Ом. Audio connections: 2x 3.5mm