Refractometer, Hand-Held, Range 1.000 to 1.050, Automatic Temperature Compensation Yes, Accuracy +/- 0.0005, Resolution 0.0005 RI, 0.001 SG, 0.2 g/dL Serum Protein, Function Determines The Urine Specific Gravity, Serum Protein, or Refractive Index By Measuring The Degree of Which Light Bends As It Passes Through The Sample, Specific Gravity 1.000 to 1.050. This item has been restricted from sale in the following state (s): []