Product synopsis Application: it is used to calibrate the sound level meters. Model: SL5868P This instrument is compatible with several standards of GB/T 3785,IEC 651 Type 2,ANSIS 1.4 Type 2.It is widely used to test the sound level of environment, mechanic, vehicle, ship and other noise. Fit for industry environment protecting,working,sanitation, teaching search and other departments. Display: 10mm (0.4″) LCD (Liquid Crystal Display) Function: LP , Leq ,LN. Frequency range: 31.5Hz~8kHz Measurement range: LP:30~130dB (A) 35~130dB (C) 35~130 dB (F) Leq :30-130dB LN .: 0-100% Resolution: 0.1 dB Accarcy:1dB Memory: Maximum value (30groups) Indicator: Low battery indicator Alarm: electron Connector:RS232C Power supply: 4x1.5v AAA (UM-4 battery Size: 236 x 63 x26 mm Weight: 170g (including batteries) Standed delivery: 1.Main Unit---------------1pc 2.Carrying Case................1pc. 3.Operation Manual..........1pc. Optional Accessories: 1.ND9 sound level meter calibrator 2.RS-232 and software 3.External rela 4.Bluetooth interface