Sensitive Sensor: 0.5s response time, no contact. Can measure noise level under any circumstances, quickly display accurate measurement result LCD Display: Large clear LCD backlight display, easy for reading even during night. Low radiation, reduce the damage to the eyes Accurate Measurement: Measuring Range 30~130dBA ; +/-1.5dB Accuracy with 0.1dB Resolution Multi-Function: Data hold function; Max/Min sound level measurement; 15 minutes auto power off, also has alarm function when voice level is up to 130dB Power Supply: Powered by a 9V Battery (Included) Professional Microphone: Features a 1/2 inch electric condenser microphone that monitors sound levels while reducing the effects of wind noise to produce more accurate readings Compact and Portable Design: Lightweight and compact construction designed to fit comfortably in your palm, suitable for measuring noise levels in factories, offices, theaters and audio systems