[Sensitive sensor] 0.5s response time, no contact. Can measure the noise level under any circumstances, quickly display the accurate measurement result. [LCD display] Large backlit LCD display, easy to read at night. Low radiation, reduce damage to eyes. [Precise 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 auto power off also has an alarm function when the voice level reaches 130dB. [Power supply] Powered by a 9V battery (Included) Product Main parameters Frequency weighting: A Measuring range: 30dB-130dB Accuracy within +/- 1.5dB Resolution: 0.1dBA Response time: 0.5 second Operating temperature: 0 ~ 40 C (32 ~ 104 F) 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. 107 g Power supply: a 9V battery Main functions Data Hold Function Max / Min Display 15 minutes automatic switch-off Large LCD screen Package content: 1x digital sound level meter 1x 9V battery How strong is too strong? Government research suggests that the safe exposure limit is 85 decibels eight hours a day. Your hearing can be damaged if you are continuously exposed to sounds at high volume. 20dB: very low, 40dB: soft, 60dB: fairly moderate, 85dB: limit 90dB: Loud, 100dB: Very loud 110dB: very low, 120dB: dangerous Wide application Some noises come 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 building, factories, offices, road cars, etc. Measuring tips: 1) When using a device outdoors, please install a windproof 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 influences from 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.