The Myron L Ultrameter II Model 4PII is a handheld, multi-parameter instrument designed for measuring conductivity, resistivity, total dissolved solids (TDS), and temperature of liquids. It features an easy-to-read LCD display that shows all four parameters simultaneously, and has automatic temperature compensation to ensure accurate readings even with temperature changes. The instrument is calibrated at the factory, and can be re-calibrated by the user using the included calibration solutions. The Ultrameter II Model 4PII is commonly used in a variety of industries including water treatment, food and beverage processing, and industrial process control.