Data storage: In the product section of the sound level meter, you can refer to the English manual. The instrument automatically stores data every 2 seconds, and the stored value is the largest noise value in 2, which can last for one year. Large screen: Super large 9, 6" with backlight which makes reading more clear and visual in dark areas. Alarm function: You can easily set an alarm threshold. When the alarm is triggered the measurement is stored and the value reached will flash for an adjustable time from 6 to 120 seconds and an audible signal will sound.When the measured value exceeds the alarm value, the sound will emit an audible beep and lock the data by flashing for 2 minutes.< /p> USB powered: By connecting a computer with a USB cable, you can download records, collect samples, and print maps, dates, etc. Wall mount type: With the hanging hole, it can be installed on the wall or free standing on the table.It can be used for families, factories, offices, hotels, hospitals, laboratories, theaters and audio systems, etc.