pH/ORP/Conductivity/TDS/Salt Features: 1.Microprocessor based designed. 2.Large LCD displays readings and temperature simultaneously. 3.Rugged design with waterproof housing. It floats on water. 4.Measuring 5 parameters: pH, Conductivity, TDS, Salinity, and temperature by just on combo electrode. 5.Automatic Temperature Compensation (ATC). °C or °F are switchable. 6.Memory function stores and recalls up to 150 points. MAX/MIN and data Lock (8200M only). 7.Simple to calibrate by one keyboard for 5 points buffer. 8.Indicate percentage of slope (PTS) after calibration 9.Auto power shut off after 10 minutes of non use. 10.Easy replaced electrode module.