Sensitive sensor: response time of 0.5 s, contactless. Can measure sound level under any circumstances, quickly display the accurate measurement result. LCD ScreenLarge backlit LCD screen, easy to read at night. Low radiation, reduces damage to eyes. Accurate measurement: measuring range 40 - 130 dBA accuracy3.5dB dB with 0.1 dB resolution. MultifunctionData hold function, max or min sound level measurement 15 minutes automatic shutdown, also has an alarm function when the sound level is up to 130 dB. Power: powered by 9V battery (included) Quantity: 1 piece Yellow color 1. Frequency range: 31.5 Hz - 4 kHz, range: 40 - 130dB 2. Precision : 3.5 dB (below 94 dB, 1 kHz reference condition), resolution: 0.1 dB 3. Frequency weighting of the sound level A frequency weighting of the sound level 4. Microphone: 1 or 2 inch polarized condenser microphone 5. Display: LCD screen 6. Display numbers: 3-1 or 2 digits 7. Response speed: 0.5 seconds 8. Time level: fast response (125 mS) 9. Alarm function: "OL" is displayed when the input exceeds the range 10 Auto power off: auto power off after 15 minutes without any operation 11. Battery: 9V carbon battery 12. Operating temperature : 0-40 (32-140) Operating humidity: 10 - 90 percent RH Storage temperature: -10-60 (14-140) Storage humidity: 10 - 75 percent RH