Patent No: ZL 200430105289.0 TX-231A: Single channel for automotive TX-231C: Single channel for home entertainment Specifications: Power requirement: 12V DC/200mA Infrared wavelength: 850nm Modulation:±75KHz Carrier frequency: - channel A: R 2.8 MHz / L-ch 2.3 MHz - channel B: R 3.8 MHz / L-ch 3.2 MHz(For dual channel) Effective distance: 10 meters(straight) Distortion:1% Frequency response: 20Hz to 20KHz Power input tolerance: normal 11V to 13V or 5V to 13V S/N ratio:>55dB Power consumption:1.0W Auto input range:0.1V to 3V(RMS)