... for Optional Purchase 3).Meets IEC 651, Type 2 Class Decibel Meter AZ-8922(30-130dB) with Free Shipping AZ-8921 & 8922 ... Stop bit, 8 Data bits. N: xxx, xdB Monitor the sound levels from traffic noise, alarm systems and workplace machinery, Multi ... case, battery, manual. Battery life :20 hours typical (9V) Dimensions (meter WxHxT) : Decibel Meter AZ-8922(30-130dB) with Free Shipping