Features: It is designed according to following standards, International Electrician Committee Standard: IEC 651 TYPE 2 & ANSI 1.4 TYPE 2.  With modern compact and portable appearance design.  Accuracy up to ±1.5dB.  Maximum value holding function to lock up the maximum reading.  Large LCD screen with digits reading.  Equipped with a sponge ball.  Auto power off design for energy saving.  Auto backlight display.  Portable, easy-to-use and handy instrument for sound quality control in factory, traffic, family, and audio system.   Specifications: Measuring range: 30-130dBA;  Accuracy: ±1.5dB;  Frequency range: 31.5Hz to 8.5KHz;  Frequency weighting: A;  Digital display: 4digits;  Resolution: 0.1dB;  Sample rate: 2 times/second;  Microphone: 1/2 inch electret condenser microphone;  Max hold: MAX;  Power supply: 9V battery (the battery is not included);  Power life: About 30 hours (alkaline battery);  Operating condition: 0-40℃ 10-80%RH;  Storage condition: -10--+60℃ 10-70%RH;  Product weight: 105g;  Package weight: 130g;  Product size: 14.2 * 5.3 * 3.5cm;  Package size: 15.2 * 6.0 * 4.2cm;   Package list: 1 * Sound Level Meter;  1 * Sponge Ball;  1 * User Manual Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.