Removable windscreen filters out wind noise 1/2 Condenser microphone Large 2 1/8” LCD screen with 4 digit readout Resolution 0.1 dB Automatic backlight with Light sensor AC analog signal output jack Pulse Width Modulation PWM output jack Fast/Slow time weighting selections Wide measuring range 30 to 130 dB, including selectable 50 dB dynamic ranges Calibration potentiometer Bar graph and over/under indication A/C Frequency weighting selections MAX value hold function to lock maximum reading Data record function, with data full indicator Fixed screw mount for tripod use USB jack for connection to PC for data record downloading, real time data sampling analysis, and printing graph and data functions requires software download from Bogen website Calendar function year, month, date for dB recordings Time display hour, minute, second Requires 4 AA batteries included , with on screen battery life indicator 10 Minute auto power off On/Off power button Designed to IEC 651 Type2 and ANSI S1.4 Type2 standards Carrying case included