1. Measuring range: 35 to 135dB Accurate MeasurementThe sound level meter of the decibel meter is 35dB to 135dB. Highly accurate with 2.0 dB. Realtime monitoring can provide you with accurate data about the sound level in the environment. Alarm FunctionMeasure and display the number in real time according to the volume of the noise. If the sound exceeds the alarm value, Quiet please will be spoken as a reminder. In addition, you can choose whether to activate the alarm or not and set your own alarm value if necessary. Versatile Charging Options This decibel meter offers two charging modes 6 AA batteries included or an AC adapter. It can be wallmounted or placed on a table for easy use, eliminating the need for handheld operation like traditional sound level meters. Digital LCD DisplayLarge LCD digital display with backlight, the reading effect is clearer in dark places. High display quality, low eye damage, low power consumption, low radiation. Wide ApplicationThe sound level meter can be used in various occasions, such as classrooms, studios, main roads, factories, construction sites, homes, offices, etc.