Amzdeal Salinity Refractometer Aquarium & Seawater - Dual Scale (1.0 to 1.070 S.G.) Automatic Temperature Compensation Hand-held ATC refractometer, can be used in the temperature 5-30  / 41-86 Dual Salinity ScaleSalt content 0 ~ 100  (0 ~ 10%) and Salt specific gravity 1.000 ~ 1.070sg. Minimum scale is 1  (0.1%) or 0.001sg, more precise Easy to UseUsing distilled water to calibrate and then you can measure the saltwater and get the result Package ContentCome with all the accessories, including Dropper, Screwdriver, Cleaning Cloth, Storage Case and User Manual Widely UseThis refractometer can be used to measure the salt content or sugar content, good for aquariums and marine monitoring