Features: This is an easy to use and handy Mini Sound Level Meter. Designed for sound quality control that measures sound level from 30dBA up ~ 130dBA. It has auto range, wide measuring and frequency range (31.5Hz ~ 8KHz), maximum hold, Frequency Weighting A and Auto Backlight. Just press one button readings are instantly displayed. A practical little tool great for noise pollution monitoring, home theater setup, health and safety compliance, vehicle noise testing, etc. Auto backlight has a light sensor on top of LCD that detects environment lighting condition. Lighting display intensifies as the environment lighting condition gets darker. The darker the environment the brighter the illumination.Also, it it reads in dBA and provides windscreen to filter-out unwanted signals. Auto Power Off, Low Battery Indication, Maximum Hold Function Specification: Model: RZ1359 Measuring Range: 30 ~ 130dBA Accuracy: ±1.5dB Resolution: 0.1dB Frequency Range: 31.5HZ ~ 8KHZ Frequency Weighting: A Sampling Frequency: 2 times/sec Microphone: 1/2" Electret Condenser microphone Operating Condition Temperature: 0~40°C Humidity: 10~80%RH Storage Condition Temperature: -10~60°C Humidity: 0~90%RH Power Supply: 3 x 1.5V Battery (not included) Size: 5*3.1*15.5cm/2*1.2*6.1in Weight: Approx.205g/7.2oz Package list: 1 * Noise Tester (Battery not included) .