Be confident in your purchase we're an Authorized Milwaukee Dealer. How cool is that?!?!? Features: Fast, accurate results with digital dual level LCD readout Easy measurement with just 2-3 drops of sample needed and results less than 2 seconds Automatically temperature compensated Simple one-point calibration using distilled or deionized water Easy to clean, stainless steel sample well with unit rated to IP65 as "dust tight" and protected against water jets Battery percent level indicator with automatic shut-off (batteries included) Specs: Range: 0 to 50 PSU: 0 to 150 ppt | 1.000 to 1.114 S.G. (20/20) | 0 to 80C / 32 to 176F Resolution: 1 PSU | 1 ppt | 0.001 S.G. (20/20) | 0.1C / 0.1F Accuracy: 2 PSU | 2 ppt | 0.002 S.G. (20/20) | 0.3C / 0.5F Light Source: Yellow LED Measurements Time: Approximately 1.5 seconds Minimum Sample Volume 100 µL (cover prism totally) Sample Cell Stainless steel ring and flint glass prism Temperature Compensation: Automatic between 10 and 40C / 50 to 104F Case Material: ABS Battery: Type 1 x 9V AA (included) Battery Life: 5000 readings Auto-shut off: After 3 minutes of non-use Enclosure Rating: IP65 Dimensions Meter: 7.6 x 4 x 2.64 inches (192 x 102 x 67 mm) Weight Meter: .93 lbs. (0.42 kg) Dimensions Package: 11 x 6.8 x 4.6 inches (268 x 172 x 118 mm) Weight Packaged: 1.46 lbs. (0.66 kg) Thousands of saltwater aquarium enthusiasts have dialed in the analysis with Milwaukee's salinity refractometer. No more visual readings. Get a digital readout within seconds accurate to 2 ppt with automatic temperature compensation (ATC).