LUTRON Sound level meter SL-4033SD comply with IEC 61672-1: 2013 Class 1 standard

Lutron SL-4033SD is a sound level meter.

Frequency and time weighting meet IEC 61672 class 1
Hold and Peak Hold function
RS232/USB PC Computer interface
Power by UM3/AA (1.5V) x 6 batteries or DC 9V adapter