Decibel Meter with A Weighting: TopTes TS-501A decibel meter uses a precise condenser microphone to capture sound. Its equipped with A-weighting facilities that measure noise levels from 30 to 130 dB with an accuracy of 1.5 dB, Frequency from 30 to 8000Hz. Perfect for monitoring noise levels at home, in communities, in automobiles, workshops, schools 2.25-inch LCD Screen with Backligh: This TS-501A sound level meter is measured noise levels are expressed in decibels (dB) and displayed on the 2.25-inch LCD screen, it easy to read on a big display design. Long press the backlight button to turn on a backlight, making it easy to view even in damn light MAX/MIN Measurement: The sound pressure level (SPL) meter has Max or Min measurement values to represent the maximum/minimum (high/low peak) value of the sound produced within a certain time, and the data hold function can freeze the current reading based on the sound measurement according to individual needs Low Battery Alert: TS-501A SPL meter is a battery-operated noise meter that comes with three durable batteries and has an automatic power-off function to extend battery life. A low battery indicator will appear on the screen when the battery is low to remind the user to replace the battery in time What you will receive: One TS-501A Decibel Meter, Three AAA Batteries, One User Manual and One Carry Case