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