J.I.Y F4 4 Channel USB Bluetooth Audio MixerFeature:- Can connect wired/wireless/capacitor microphone, applicable to the family KTV, campus speech, meeting etc.- Built in reverb effect, by adjusting knob to adjust the reverb depth and delay effect- USB/MP3 Jack, USB Jack can be connected to U disk or MP3 and other portable audio equipment- You can call up professional audio- 3 stage equalization regulate,by adjusting knob to adjust the reverb depth and delay effect.- Two sets of stereo output, one earphone monitor and one auxiliary effect output.- There are 6 modes of music: nature, rock, jazz, classical, Soft, Mega bass. - bluetooth access in one second. Built-in bluetooth function to support wireless docking of most bluetooth-enabled electronic devices.  Specification: Model: C91151Name:Mini 4 Channel USB bluetooth Portable Mixer Live Studio Audio Mixing Console Material: Metal+plasticInput channel: 4 channelsInput: 220V AC 50HzPhantom supply voltage:+48VConsumed power :18 WSize(approx): 23.5x20x3.5cmMaximum input level of microphone: +24dBuMaximum input level of line: +24dBuMaximum output level: +26dBuMain level meter: 5 stage ledFrequency response: 20Hz-20kHz + 0.5dBCommon mode rejection ratio (MIC 1kHz): > 75dBTotal nil distortion (THD+N): < 0.01% (channel input to mixer output).Crosstalk (1kHz): > 85dBNoise (22Hz to 22KHz): equivalent input noise -116dbu residual output noise < -80dbuMono / stereo channel EQ:High frequency, broom type, +/-15db, 12KHzLow frequency, broom type, +/-15db, 80KHzHigh / medium frequency, peak valley type. +/-15db, 2.5KHzFit for:applicable to the family KTV, campus speech, meeting etc. Package included:1x Mixing Console1x AC power Adapter1x User Manual Note:-Do not use this device near the TV, radio, stereo, cell phone or other electronic device, or it may cause noise.-Please use a soft dry cloth for cleaning equipment-Do not set any equalizer and level knob to the maximum position, otherwise it may cause acoustic feedback and damage the speaker.