Digital display: displays the maximum number of 1999 .Data storage function .Background light .Battery low indicator .Over range indicator .Date and time Manual and automatic range selection Response speed Maximum hold function echnical parameters Measuring range: 30dB ~ 130dB Accuracy: ± 1.5dB in the reference sound pressure level 94dB @ 1KHz Resolution: 0.1dB Sampling rate: 2 times / sec Power: 6 x1.5VAAA (not included in the package)Dimensions: 278 X80 x38mm Functional specification: The sound level meter with International Committee of IEC651 Type 2 and American national standard ANSI S1.4 Type2. The measurement range of 30 ~ 130 dB and auto shift function. A and C weighted network selection. Fast / slow (FAST) (SLOW) reaction rate selection. The maximum value (MAX) lock function. Can be directly recorded 16000 pen voice data, according to the needs of the user can be extended to 128000 pen. AC signal output: 0.707Vrms / full scale for each file, the output impedance of about 600Ω, (30 ~ 130 DBfile NA). DC signal output: 10mV/dB, the output impedance of about 100Ω.Power: 1.5V 7 6 batteries or DC 9V 100mA DC voltage power converter, the maximum may not exceed DC 9.5V. Record items: 16000 (expandable to 128000 pen) Operating temperature: 0 ~ + 40 degrees Celsius. Operating Humidity: 10 ~ 80% RH. Storage temperature: - 10 to + 60 degrees Celsius. Storage Humidity: 10 ~ 70% RH. Package Contents1 * MS6701 Sound Level Meter1 * Earphone 1 * Computer RS-232 cable1 * CD Softtware1 * Operation manualLight shooting and different displays may cause the color of the item in the picture a little different from the real thing.Please refer to the received product. Thank you for your understanding.