Features:  Auto Ranging  Fast/Slow time weighting selection  32000 Reading Internal Memory (Data record function)  Data Logging function  Max Hold function  Frequency weighting: A/C  High Accuracy  Bar graph display  AC/DC function  PC Interface ((Compatible with Windows 10, 8, 7,  Vista and XP)  When connected to computer, the measurement are live on computer screen too  White Backlight  Adjustable Over / Under alert threshold via computer interface  Maximum data recording limit can be adjusted via the PC interface  Time display  Auto-off function setup  Low Battery Alert  Tripod Mount (Tripod not included)  Includes CD Software ( language: English), AC/DC wire & batteries  CE Certified & RoHS Compliant Specifications:  Standard Applied: IEC651 type 2, ANSI SI .4 type 2  Calibration sound source: 94dB @ 1kHz  Measurement range:30~130dBA  Accuracy:+1.5dB(reference sound pressure standard,94dB@1KHz)  Record Interval: 1~60 sec / 1~60 min / 1~24 hrs  Frequency response: 31.5~8.5KHz  Resolution:0.1dB  Frequency weighting: A/C  Analogy bar graph: 2dB/1 Bar graph  Measurement Unit: dBA / dBC  Sampling rate: 2 times/second (FAST), 1 time/second (SLOW)  AC signal output: 4Vrms/ full barograph, output impedance is approx. 600 ohm  DC signal output: 33mV/dB  Dynamic characteristic: FAST (high speed) / SLOW (low speed)  Data storage quantity:32000 readings  Windows Compatibility: Windows 10, 8, 7,  Vista and XP(Do not run in Mac OS)  Power supply: 4pcs x  AA Size 1.5V battery or USB Power Cable  Item Weight: 7.4 ounces  Product Dimension: 9 x 2.5 x 1.5 inches  Shipping Weight: 14.6 ounces  Shipping Dimension: 9.6 x 4 x 2 inches Set Includes  1 x Sound Level Meter  1 x English User Manual  1 x CD Software (English & Chinese)  1 x USB Cable  1 x AC/DC line  4 x AA Battery  1 x Carrying Pouch