This meter is featured with wide measuring range (30-130dB). It's portable and easy to use and handy instrument for sound quality control in factory， office， home， school and construction site. <br><br><strong>Features:</strong> <br>Wide measuring range: 30-130dB. <br>Fast/Slow response and Maximum hold function. <br>Equipped with sponge ball. <br>Auto power-off after working 2 minutes(power on normally); if you press the switch button for 3s， it will not power off unless you press the button again. <br>AC/DC analog signal output. <br>Power supply: USB interface or 4 * AA batteries. <br>Portable， easy to use and handy instrument for sound quality control in factory， office， home， school and construction site. <br><br><strong>Specifications:</strong> <br>Measuring Range: 30-130dBA or 35-130dBC <br>Accuracy: ±1.5dB <br>Resolution: 0.1dB <br>Frequency Range: 31.5Hz to 8.5KHz <br>Level Range: 30~80dB， 40~90dB， 50~100dB， 60~110dB， 70~120dB， 80~130dB， 30~130dB <br>Linearity Weighting: 50dB <br>Frequency Weighting: A/C  <br>Digital Display: 4 Digits <br>Sample Rate: 2 Times/sec <br>MAX Hold: "MAX" <br>Over Indication: OVER/UNDER <br>Time Weight: FAST/SLOW <br>Microphone: 1/2inch Electret Condenser Microphone <br>Power Supply: 4 * 1.5V AA Batteries(not included) or USB 5V 100mA <br>Operation Environment: 0-40 ℃ 10-80%RH <br>Storage Environment: -10-50℃ 10-80%RH <br>Dimension: 230 * 70 * 35mm / 9 * 2.75 * 1.38in (L * W * H) <br>Weight: 269g / 9.48oz <br>Package Size: 29 * 14 * 6.5cm / 11.4 * 5.5 * 2.56in (L * W * H) <br>Package Weight: 459g / 16.19oz <br><br><strong>Package List:</strong> <br>1 * Sound Level Meter <br>1 * Sponge Ball <br>1 * USB Cable <br>1 * CD <br>1 * User Manual (English)