Portable Sound Level Meter: A handy little tool that's ideal for noise monitoring, home theater setup, health and safety compliance, vehicle noise testing, and more.HD Digital LCD: Large, readable LCD display with backlight for quick display of measurement results, clear and easy to read. Power supply: 3 AAA batteries (not included), low battery indicator, automatic shutdown after 10 minutes, convenient to save energy. Versatile: measurement range from 30 to 130 DBA. MAX / MIN / data hold function - automatic shutdown - battery indicator: directly check the remaining battery. Multiple uses: designed to meet the measurement requirements of sound quality control in various environments. Ideal for testing music recording, noise complaints from neighbors, industrial installations, office installations, voice therapy, etc.