The Milwaukee Instruments Salinity Refractometer allows you to measure salinity like the professionals.Features:Range is from 1.000 to 1.070 Simple to use: simply place one drop of your sample on the prism and read the results on the scales immediatelyAdjustable focus and easy to read numbers for good resolution and zero adjustment screw for calibrationCalibrated and adjusted to measure at 20°C (68°F). Comes with automatic temperature compensation function.