Analog Refractometer Salinity Range 1.000 to 1.070 Automatic Temperature Compensation Yes Accuracy +/-1 Percent Resolution 0.001 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 Height 1 in Dia 1 in