1、Maximum and Minimum Value Locking: The maximum and minimum value locking is a display function. After being enabled, the maximum and minimum value measured from the opening time to the current measurement time (MAX: maximum value locking, MIN: minimum value locking). 2、Two Screen Display Modes: There are two screen display modes, normal mode and night mode. The screen can be lit with one key in case of dim light. 3、Film Keys: The film keys have better feel and longer life, which can indirectly improve the working efficiency of the sound level meter itself. 4、Hanger Back Clip : When your hands are occupied during work, you can hang the digital sound level meter on your clothes or belt. 5、Removable Wind Shield: When the measured value deviates, it is convenient to calibrate and zero the noise sensor. 6、One Click Switch to FAST and SLOW: FAST, sensitive, fast detection. SLOW, more stable detection and more accurate data. 7、One Key Value Locking: One key "HOLD" can lock the currently detected noise value, providing you great using experience. Item Type: Digital Noise Meter Product Material: ABS Color: As Pictures Shown Weight: Approx. 150g / 5.3oz Accuracy: ± 1.5dB (at the quasi reference sound pressure level 94dB at 1KHz ) Frequency Response: 20Hz-8KHz Dynamic Range: 50dB Measuring Range: 30-130dBA Frequency Privilege: A Right Display Digits: 4 Digits, Resolution 0.1dB, Sampling Frequency Twice Per Second Load Indication: "OVER" and "UNDER" Symbols Dynamic Characteristics: FAST (Fast) and SLow (Slow) Reaction Rates Microphone: 1/2 Inch Condenser Microphone Operating Temperature: 0-40 °C, 10-80% RH (Non Condensing) Battery: 3 AAA Battery (Shipped Without Battery) Product Size: Approx. 158x60x25mm / 6.2x2.4x1.0in (Without Hanger Back Clip) Application: It can be used for noise engineering, quality control, health prevention and various environmental noise measurements, such as factories, offices, roads, homes, and other scenes 1 x Host 1 x Screwdriver 1 x Manual