CHECK MATE 140: Microphone: Electret condenser microphone, Accuracy: ±1.5 dB, Level Range: Lo = 35 ~ 80 dB, Med = 50 ~ 100 dB, Hi = 80 ~ 130 dB, Frequency Weighting: A , C, Time Weighting: Fast , Slow, Auxiliary Outputs: AC Signal Output, Dynamic Range