Check sound levels economically. Built-in 0.5 in. microphone. Fast or slow response settings. Max hold select switch. A and C weighting selectable. Analog output for connection to chart recorders, data loggers etc. Easy calibration adjustment. Threaded insert for tripod mount. Economy priced. Range: 54 to 126 dB in 7 ranges (manual). Accuracy: plus/minus 3 db. Resolution: Analog continuous. Power source: 9 volt battery. Dimensions 7.1 x 2.7 x 1.4 in. Weight 5.1 oz.