Features: Large LCD display (2.0 x 1.5 inches (52 x 38 mm)), easy to see measurements A multi-measuring instrument that can measure 6 types (PH, ORP, conductivity, TDS, dissolved oxygen, salt). Can be used as a dissolved oxygen meter with standard accessories. Record the data on an SD card (1 - 16 GB) and manage data in the PC's EXCEL. RS232C interface is included for data communication. Measurement items: PH, ORP, conductivity, TDS, dissolved oxygen, salt (sensors sold separately except melted oxygen). Measurement range: 0 - 14PH(PH), -1999 - +1999 mV (ORP), 0 - 200 mS (conductivity), 0 - 132000 ppm (TDS), 0 - 60 °C (temperature), 0 - 20 mg/l (dissolved oxygen), 0 - 12% (salt) Resolution: 0.01PH, 1mV (ORP), 0.1μS-0.1mS (conductivity, varying range), 0.1ppm - 100ppm (TDS, different depending on range), 0.1°C (temperature), 0.1 mg/l (dissolved oxygen), 0.01% (salt) Accuracy: ±(0.02PH+2dgt)/PH, ±(0.5%rdg+2dgt)/ORP, ±(2%F.S+1dgt)/conductivity, ±(2%F.S+1dgt)/TDS, ±0.8°C/temperature, ±0.4mg/l/melt oxygen, ±0.5%/salt Probe correction: 0 - 50 °C (temperature / automatic), 0 - 50% (salt, manual), 0 - 8900 m (altitude, manual) Functions: Data hold, MAX value display, MIN value display, ℃/℉ switch, measurement item switch, data logger, calibration, auto power off. Data Logger: Automatic (1 - 8 hours, 59 minutes, 59 seconds setting), manual (press the button to record 1 - 99 points). Data output: RS232 serial interface SD card: 1 Operating temperature and humidity: 32 - 122°F (0 - 50°C), 85% RH or less (without condensation). Power supply: 6 x AA batteries or AC adapter (sold separately). Standard accessories: 6 x AA batteries, 1 x Carrying case, 1 x SD card, 1 x Melted Oxygen Electrode (OXPB-11), 1 x Diaphragm Set (OXHD-04, 2 pieces), 1 x Electrolyte (OXEL-03, 1.1 fl oz (30 ml) x 1, instruction manual.