The AET-933 is a lightweight and user friendly sound level indicator offering 4 measurements ranges (3 manually selectable, 1 auto range). It offers selectable A or C frequency weightings and a choice of either fast or slow time weightings. It is designed to match the accuracies required of IEC 61672:2013 at 1.4dB. 4 measurement ranges 30 to 80dB 50 to 100dB 80 to 130dB 30 to 130dB (Auto range) Over/under range indicator 1dB resolution Selectable A or C frequency weightings Frequency range 31.5hz to 8mhz Selectable fast (125ms) or slow (1s) time weightings Precision inch electret condenser microphone Lmax (LAFmax, LASmax, LCFmax, LCSmax) Lmin (LAFmin, LASmin, LCFmin, LCSmin) 35mm LCD display with bargraph and function indicators LCD display backlight Data hold Max hold displays highest measured value Min hold displays lowest measured value Low battery indicator Auto power off after 15 minutes of no activity Supplied with soft carry case, wind muffler, battery and 2 year warranty