1. The sound quality is clear and significantly better than other types of amplifiers. 2. Equipped with Bluetooth, it can receive Bluetooth audio. 3. With a level indicator, you can also enjoy turning off the lights while listening to music. 4. The potentiometer is equipped with a switch, which can turn off the power supply to the board when not needed. 5. Easy to operate, the volume knob has a switch function, and it can be turned counterclockwise to turn off the power supply of the module. Power supply voltage:DC 4.5-5V (do not exceed, otherwise the chip will burn) Output power:5W/2 Ω/5V or 1.8W/8 Ω/5V Interface:3.5 audio dock Power cord:USB to DC005 cable Circuit board size (excluding potentiometer extension):length 90.5mm x width 33mm x height 22mm. Fixed hole distance:84.4mm x 26.5mm (aperture 3mm) It's DIY kits, needs to finish by yourself. Color:As Shown Material:Plastic+Metal Package Contents: 1 * Bluetooth Speaker Kit