1. Calibrated sound source: 94dB/1KHz 2. Measurement range: 30-130 dB, 35-130dB 3. Resolution: 0.1dB 4. Frequency response: 31.5Hz-8500Hz 5. Rated current: 70mA 6. Standby current: 5uA 7. Power supply: 3.7V/1000mAh 8. Charging time: 1.5h 9. Use time: 8h 10. Working temperature: 0 to 50 degrees Celsius 11. Working humidity: 10-80% 12. DC voltage range: 300mV-1300mV 13. DC impedance: 120R 14. Can be used for noise engineering, quality control, health prevention and environmental noise measurement