Features 1、DC voltage between 5V and 12V can be powered, with reverse connection protection. 2、The VU meter is a voice‑activated sensor, so there is no need to connect audio, just power on the product, it will flash when there is a sound. 3、The louder the sound, the more the LED will light up from bottom to top. As the sound fluctuates, the LED will flashing with the music. 4、Using an independent comparator circuit, although the circuit is slightly more complicated, the structure and principle are easier to understand. 5、Equipped with anti‑reverse connection protection diode, which can effectively prevent the circuit from being burnt due to the reverse polarity of the power supply. Specification Item Type: VU Meter Material: Plastic Size: Length 10cm / 3.9in x width 3cm / 1.2in; Lamp Beads: 5mm Round Head Fog-like Led, Uniform and Not Dazzling (multi-color Optional); Power Supply: DC 5V-12V is Available, the Board Comes with a Microusb Socket, You Can Use the Corresponding Mobile Phone Charging Cable to Plug in the Power Supply, and 2 Pad Ports Are Reserved for Users to Lead Their Own Wires; Package List 1 x VU Meter