Unipex SA2017 portable meeting amplifire has 200-270 MHz frequency, multiple silent installations to avoid signal interference and noise, voltage DC9V, host system - frequency response 100Hz-16KHz, host system - input signal cable Cx1 wireless MIC x1AUX x1, effective use of period - radius than 50m, size 180 x 110 x 300 mm, power supply AC115V/230V - optional - DC 9V/DC 12V / 1.2Ah using sealed lead-acid maintenance, free batteries.