Refractometer, Salinity, Range 1.000 to 1.070, Automatic Temperature Compensation Yes, Accuracy +/- 0.001 SG, +/-1 ppt Salinity, Resolution 0.001 SG, 1 ppt Salinity, Function Determines The Specific Gravity of Salt Concentration By Measuring The Degree of Which Light Bends As It Passes Through The Sample, Specific Gravity 1.000 to 1.070, Features All Metal Housing, Calibration Screw, Glass Prism, Non Roll Stand, Rubber Eye Cup, Rubber Grip, Scale Display, Single Hinged Daylight Plate, Width 1 in. This item has been restricted from sale in the following state (s): []