[Sensitive sensor] 0.5s response time, no contact. Can measure the noise level under any circumstances, quickly display the accurate measurement result. [LCD Display] L backlit LCD screen, easy to read at night. Low radiation, reduce damage to the eyes. [Accurate measurement] Measuring range 30 ~ 130dBA; Accuracy of +/- 1.5dB with a resolution of 0.1dB [Multi-function] Data hold function; Max/Min sound level measurement; The 15-minute automatic power-off also has an alarm function when the voice level reaches 130 dB. Sound meter Main settings Frequency weighting: A Measuring range: 30dB-130dB Accuracy within +/- 1.5dB Resolution: 0.1dBA Response time: 0.5 seconds Operating temperature: 0 ~ 40C (32 ~ 104F) Operating humidity: 10 ~ 90% R.H. Storage temperature: -10 ~ 60 C (14 ~ 140 F) Storage humidity: 10 ~ 70% relative humidity Dimensions: approx. 170 (L) x 58 (W) x 35 (H) mm (6.7 x 2.3 x 1.4 inches Weight: approx. 107g Power supply: one 9V batteryBatteries not included Main functions Data hold function Max / Min display 15 minutes of automatic shutdown L LCD screen Box contents: 1x digital sound level meter How loud is too loud? Government research suggests the safe exposure limit is 85 decibels for eight hours a day. Your hearing may be damaged if you are continually exposed to loud sounds. 20dB: very weak, 40dB: soft, 60dB: fairly moderate, 85dB: limit 90dB: Loud, 100dB: Very loud 110dB: very weak, 120dB: dangerous Wide application Some noise comes from the graph above: Pet birds / Car noise / Washing machine / Urban construction / Musical instruments This decibel meter is ideal for industry and the home. It can easily measure the noise level of household appliances, neighbor's pets, city construction, factories, offices, road cars, etc. Measuring Tips: 1) When using a device outdoors, please install a wind-resistant ball on the head of the device to avoid the effects of wind. 2) If you want to measure the sound level from A, you cannot ignore the influences of other sources. 3) Please measure several times to get a relatively stable reading. Please attention: 1) Please remove the 9v battery if it is not used for a long time. 2) Please do not use it in high temperature or humidity environment.