2. Features and Functions: 1). Accuracty: +-1.5dB ( In Standard sound: 94dB@1KHz 2). Range of Measurement: 30~130dB 3). Frequency Response Range: 31.5Hz~8.5KHz 4).Frequency Weighting:A (Ambient Noise) Weighting 5). Response: Fast 6). Connecting computer with USB cable, you can down-load records, collect samples and print chart and date.(Only for model 525B) Technical Parameters Meter Description: 1). Hooks 2). USB outlet 3). Alarm Light 4). Microphone Sensor 5). Display:Three 3 inch dightal tube display to display sound Level value 6). Tripod Mounting Screw:1/4", the meter can be mounted on a tripod with this hole 7). Audio Outlet: when there is an alarm with 2KHz Signal, it can drive the loudspeaker to alarm 8). Calibration Knob. The meter has been calibrated before ex factory. Do not adjust the meter 9). Buttons