Easywin Saltwater Marine Aquarium Salinity Portable Refractometer Meter Fish Tank Reef Dual Scale (1.0 to 1.070 S.G.) Measure salt water or salinity of water, ideal for aquariums and marine monitoring Measures on 2 scales, Specific Gravity (D 20/20) and parts per thousand (?). Features automatic temperature compensation (ATC) Comes with pipette;mini screw driver;cleaning cloth;instruction manual rugged body with durable & comfortable non-slip rubberized grip handle