Feature: 1. 4 IN 1 DECIBEL METER: This decibel meter has multiple functions, having a decibel meter is equivalent to having a thermometer, hygrometer and clock at the same time. 2. 11IN DISPLAY SCREEN: This large screen decibel meter has an 11 inch LED display with adjustable brightness for a clear, easy to use display. 3. HIGH ACCURACY: The sound level meter uses an intelligent air semiconductor sensor to test decibel temperature and humidity values, making it more sensitive, accurate and stable. 4. WIDE APPLICATION: The sound level meter can be applied to noise engineering, product quality control, health prevention and treatment, etc. 5. USB CHARGING: This decibel meter has a built in 2000mAh lithium battery power supply with a 10ft USB charging cable so you can charge it anywhere. Specification: Item Type: Wall Mounted Sound Level Meter Material: ABS Display Method: LED Screen Atmospheric Pressure: 12.5 PSI- 15.4 PSI Sampling Time: 1.5 S Detection Temperature Range: -10℃-50℃ Storage Temperature: -10℃-60℃ Operating Environment, Storage Humidity: 20%-85% Detection Humidity Range: 20%-85% (Accuracy: 5%) Charging: 1000 mA 5V DC Battery : 1 x 18650 2000mAh (shipped with built in battery) Unit: dBA Measurement Range: 30-130dBA Accuracy: ±1.5dBA Frequency Range: 50Hz-8.5kHz Frequency Weighting: A Screen Display: 0.1 dBA Sound Meter Level (Unit dB): Green 1: 55.0 or less Green 2: 65.0-55.0 Orange1: 75.0-65.0 Orange2: 85.0-75.0 Red1: 95.0-85.0 Red 2: 95.0 or more Temperature Rating (unit ℃): Green: 20-30 Orange: Below 20 Red: Above 30. Package List: 1 x Wall Mounted Sound Level Meter1 x Instruction1 x USB Cable1 x Installation Sticker2 x Screw2 x Expansion Tube