Salinity Refractometer Portable Seawater and Marine Tester for Aquarium Fishkeeping for 0-100 PPT with Automatic Temperature Compensation(ATC)

For measuring salt water or salinity in a water sample for Salt Water Aquariums. Measures on 2 scales, Specific Gravity and parts per thousand. Features automatic temperature compensation. Includes, eyedropper, small screwdriver, user manual and a cleaning cloth. Best to calibrate it with distilled water or a salinity calibration fluid for accurate results.