Check the listing for details. EQ7 Car Audio Headset Amplifier 2 Channel Audio Mixer Equalizer. Condition: New. Listed at 298.59 USD. 2. Basic parameters: 7-band sound equalizer preamplifier gain, 4580 classic operational amplifier provides 5X amplification (14dB); The input impedance is 20K, and the output impedance is 600 Ω. 4. 3.5mm interface: The 3.5mm input interface supports a 4-pole plug, and the output is connected to a headset with a microphone, which can be used for normal voice calls on the mobile phone. In addition, there is a terminal of interface. 5. Aluminum alloy material: 7-band audio equalizer is made of aluminum alloy, with high strength, resistance, stable performance, DC5V - 12V power supply, dual channel sound. It is widely used in home/car audio/mobile phone/computer/game console and other devices. PLEASE NOTE: If you have any doubts or questions about the item, please don't hesitate to contact us.