AS804 Digital Sound Level Meter 30-130db Decibel Meter Noise Monitoring Tester Smart Sensor Noise DB Detector Analyzer, Diagm Description of Audio Noise level meter
① ON/OFF button
② Max/Min button
③ LCD back light button
④ Hold Switch button
⑤ LCD Display
⑥ Calibration control
⑦ Battery Door
⑧ Electronic condenser Microphone
