4 units of sound production, dual speakers, dual diaphragm 9D three-dimensional surround sound triple frequency equalization, and explosive sound effect. Portable operation, independent knob, independent volume control, and more free to adjust sound effects. Dual mode use, wired/Bluetooth dual mode, built-in chip, enjoy life. Widely compatible with devices. USB connection to computer interface can provide power. 3.5mm audio cable can be connected to mobile phones, computers, televisions, etc.