Extech Digital Sound Level Meter has analog bargraph with 50dB range updates every 40ms. +/-2dB accuracy with 0.1dB resolution, A and C weighting, AC analog output, Record Max/Min values over time, Auto power off and Max Hold functions, Utilizes 0.5 inch (12.7mm) condenser microphone, tripod mountable, 40 to 130dB measuring range, fast/slow response time. Applications include monitoring workplace machinery , installing audio and alarm systems.