Features: 1. 100% brand new and high quality 2. This meter has instantaneous sound measure function. 3. The measurement range is 0?130 dB 4. It has two equivalent weighted sound pressure levels, A and C. 5. Suitable for AC and DC signed output for frequency analyzer level re corder, FFT analyzer, graphic recorder etc. Specification: Condition: 100% Brand New Brand: SMART SENSOR Model: AS824 Accuracy: 1.5 dB(under reference conditions) Frequency range: 31.5 Hz to 8.5KHz Linearity range: 50dB Measuring level: 30?130dBA,35?130dBC Frequency weighting: A,C Digital display: 5 digits Resolution: 0.1dB Display: 0.5 secretary Bar graph: 50 dB scale at 1 dB step for monitoring current sound pressure level display period: 50 mS Level ranges: 30?80 dB; 50?100dB; 60?110dB; 80?130dB; Over indicate over range: Under indicate less than lower limit of the range. AC output:0.707 Vrms at FS output impendance approx 600 DC output:10 mV/dB output impedance approx 100 Time weighting: Fast/Slow Microphone: 1/2 inch Electret Condenser microphone Max: Maximum hold Power supply: 9V battery(not included) orDC9V 100mA Self calibration time: 10 sec(every turn on) Operating Temperature: 0 to 40 Operating Humidity: 10% to 80% RH Storage Temperature: ?10 to 60 Storage Humidity:10% to 70% RH Weight: Approx. 664g / 23.4oz Size: Approx. 224 * 66 * 33mm / 8.8 * 2.6 * 1.3in Package List: 1 * Digital Sound Level Meter 1 * Power Supply DC 9V Cable Note: New-style and old-style are shipped randomly