Features: Measurement range 30 ~ 130dB (dB) Accuracy: +1.5 dB (reference sound pressure level, 94dB @ 1kHz) Dimensions: 210 * 130 * 30MM Frequency response: 31.5Hz ~ 8.5kHz frequency weighting: A Response time: Fast Alarm switch indicator/Condenser microphone sensor Microphone: 1/2 inch condenser microphone Digital Display: 3pcs 3-inch digital tube display three Power supply: DC 5v 1A micro USB working environment: 0 - 40 degrees (32 degrees Fahrenheit to 104 degrees Fahrenheit), 10 - 80%RH Storage of Temp. and humidity: -10~60C. 10~70%RH Special Function: 1. Data Storage Function, For one year, 2 seconds per data 2. Data Export Function Package content: 1 x SW-525b sound level meter 1 x Warranty 1 x Mnual 1 x Cable DC 5v 1A micro USB cable The Sound Level Meter is versatile device for measuring sound intensity in an acoustic envieronment-lound or soft; high pitched, low-pitched, or Broad-band; inter-mittent or continuous, This meter can be used in measuring noise of various occasions and addpiances such as factory, office, home, traffic route, acoustics, air-conditior refrigerator, etc....