Features: Size: approx 7.9x5.9cm/3.1x2.3inches. VU meter audio is the most basic tool in audio equipment, easy to install and use, can improve work efficiency, save for time and energy. Compact design, easy to carry and store, with pointer dial, high accuracy, can directly display measurement results. Suitable for DIY, recording studio, home audio, car audio transform, etc. Made of highquality material, with excellent durability and stability, has good performance and long service life. Specifications: Material: plastic Size: approx 7.9x5.9cm/3.1x2.3in Wiring Reference Backlight bright and dark adjustment vu meter for head 2 beat amplitude adjustment for DC input 12V Vu meter for head 1 beating amplitude adjustment If the input signal is a mobile- phone, AC/DC12-18V MP3, put DIP switches 1 and 3 Hit the ON end, the input is c0onn-S Amplifier output, dial 2 and 4LGR Hit the ON end Low level input MP3 high level input Note: Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x VU Meter