We are offering sound level meter. this low cost sound meter has been designed for quick noise surveys and sound level checks. Despite its excellent range of features, it is very easy to use and the large backlit display helps when measuring in poor light conditions. large, clear display with back-light30 to 130 db(a) auto ranginga and c frequency weightingfast and slow time weightingmaximum and minimum sound level readingshold button holds the currently displayed levelincludes wind shield, carrying case and battery specificationsdisplayindicators resolution / accuracyfrequency rangelevel rangefrequency weightingmicrophonetime weightingdynamic rangebatterybattery lifetemp. & humiditydimensions 4 digit lcd with back light, update rate 0.5slow battery, freq. & time weighting, min/max0.1db / 1.5 db (ref 94 db @ 1 khz)31.5 hz to 8 khz30 to 130 db(a), 35 to 130 db(c)a and c1/2" electret condenserfast (125ms) and slow (1s)50 dbone 9v battery (supplied)about 50 hours (alkaline battery)5c to 40c, below 80% rh8" x 2.1" x 1.5", 6 ounce (inc. Battery)200 x 55 x 38, 170g (including battery) due to its auto-ranging feature and simple push-button operation, this sound meter is extremely easy to use. Just switch it on and it is measuring with the most common settings: "a" frequency weighting and "fast" time response. At the push of a button you can change it to display the "c" weighted sound level or change to "slow" time response. The large display with back light make this meter ideal for measuring noise levels where the natural light is poor.