1.This equipment has been designed to meet the measurement requirement of Safety Engineers, Health, Industrial Safety offices and Sound Quality control in various environment,which include factory,office,traffic, family 2.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 ~ 8.5KHz), maximum hold, Frequency Weighting A and Auto Backlight. Just press one button readings are instantly displayed. 3. A practical little tool great for noise pollution monitoring, home theater setup, health and safety compliance, vehicle noise testing, etc. 4.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. 5.The darker the enronment the brighter the illumination. Also, it it reads in dBA and provides windscreen to filter-out unwanted signals, Manufacturer: LLAWQSM