Features: 1. Professional sensor for excellent sensitivity and precision 2. The quality of the sound can be measured in various environments without contact, and the test results can be displayed quickly and accurately. 3. High-intensity backlight screen display for easy reading at dim environment. 4. With automatic shutdown function, automatic shutdown after 3 minutes without operation, energy saving and environmental protection 5. Widely used in automotive noise testing, industrial equipment noise testing, home noise testing, etc. Specification: Condition: 100% Brand New Brand: SMART SENSOR Model: AS804 Accuracy: 1.5dB Frequency Range: 31.5Hz to 8.5Hz Measuring Level: 30-130dBA Resolution: 0.1dB Over Range: LCD show Over Time weighting: Fast Max: Maximum hold Min: Minimum hold Power Supply: 3 * AAA 1.5V alkaline cells(not included) Microphone: 1/2 inch Electret Condenser microphone Operating Temperature: 0-40 ℃ Operating Humidity: 10%-80%RH Storage Temperature: -10-60 ℃ Storage Humidity: 10%-70%RH Weight: Approx. 111g / 3.9oz Size: Approx. 155 * 50 * 25mm / 6.1 * 2.0 * 1.0in Package List: 1 * Digital Sound Level Meter