What's in the box:

4-Channel Microphone Mixer Support Stereo Output Mini Audio Mixer with Reverb Treble and Bass Adjustment (Standard)

Features:
4 microphone input interfaces (6.35mm), can be connected to 1~4 wired microphone.
4 channels independent knob for adjusting volume, can adjust the volume of 1~4 channels of microphone flexibly.
Reverb adjustment function: E-cho knob can adjust the reverberation effect.
High and BASS adjustment function: BASS knob to adjust the BASS level of the microphone; and the Treble knob adjusts the high pitch of the microphone.
2 audio output interfaces: 6.5mm MIC mono output + RCA stereo audio output.
Standard USB 5V power supply, suitable for outdoor mobile power use, with wider application range.
Compact design, and can be compatible with any devices.
Simple installation: input and output plug and play easy installation, enjoy music instantly.

Specifications:
Material: Metal
Color: Black
Input interface: 6.35mm
Output interface: 6.35mm + RCA
SNR(Signal to Noise Ratio): 120dB(A)
Degree of distortion: less or equal to 0.02
Frequency response: 20Hz-20kHz
Output noise: less than 0.1mw
Output impedance: 100kohm
Power Supply: USB 5V
Item Size: 165 * 82 * 38mm / 6.49 * 3.22 * 1.49in
Item Weight: 480g / 16.93oz
Package Weight: 630g / 22.22oz
Package Size: 20 * 18 * 5.5cm / 7.87 * 7.08 * 2.16in

Packing List:
1 * 4-way Microphone Mixer
1 * USB power cord