Compact and easy to use while providing you accurate calibration with your sound level meter. A great instrument similar with some expensive sound calibrators. Characteristics: IEC 60942:2018, standard class 2 Stable and accurate even in conditions of high humidity Suitable for all microphone head in a 1/2" (13.2mm) microphone size 1K Hz calibration frequency at 3 levels - 114dB, 94dB and 104dB Vivid LED display with stability and low power indicator Easy to bring around, battery-powered. LED indicator: 1 green/Red: ready/low power; 3 green: 114/101/94dB Item Specifications Frequency of Calibration: 1000Hz Precision of frequency: ±1.7 % Calibration Level: 94dB (decibel) 104dB (decibel) 114dB (decibel) Accuracy of Sound Pressure: ±0.4dB Diameter of the microphone head cavity: 13.2mm (1⁄2") Period for stabilization: ten seconds Full Distortion: