Summary: 1. With digital display stereo MP3 input2. Bluetooth function3. 48V fantasy power supply for condenser microphone4. Built-in digital effects5. Five-segment effect level monitor indication6. Seven-band stereo equalization7. Recording input with stereo function8. Low noise microphone input with interface Feature: 1.Built-in 48V Phantom power for confenser microphones use professional recording;2.Built-in 7-Band equalizer;3.2 Line (L/R) audio output;4.1 to send output, 1 return input;5.1 Line to high-fidelity headphone output power (1W)6.Headphone Monitoring function, Bluetooth Function, Recording Function High-performance microphone pre-amplifier with phantom power(+48V).Built-in mute switching mode power supply.High-performance three colors output level meter.24-400Hz adjustable dual channels sub output.With MP3, USB input players.Exquisite color crystal buttons channel switch.SMT automated technique for strict control the consistency of the products.  Specification:Frequency Response:20Hz-20KHz, ±0.5dBTHD+N: -30dB input to mix, mic gain 30dB,<0.007%Mic Input Ein: MIC EIN@Max gain,150 ohms source impedance -128dBBus Noise: Noise(20Hz-20KHz measurement bandwidth)Audio Mixing:MIX@MAX faders down<-85dB)Crosstalk Between Channels:>96dBCrossover Fader Position:>96dBAux Send Port:>86dBOutput Level Meter:L/R mix output level is 12 segment of LED indicatorPower: AC input 100 or 240V 50/60HzPower Consumption:<30W   Package includes:1x 4 Channel Mixer1x Power Adapter1x Manual