Brand new Salinity Refractometer that is used to measure the salinity levels of saltwater aquariums and the worlds oceans. Calibrate with either distilled water or a 35ppt Salinity standard. This listing includes (1) 3.6ml Vial of 35 Parts Per Thousand (ppt)/1.0264 Salinity Specific Gravity Salinity Calibration Standard. Wipe off the saltwater after each use. Rinse off the daylight plate and prism with distilled water to remove the corrosive salt water after each use to ensure that this Refractometer will last for a long, long time. This unit comes with Automatic Temperature Compensation or "ATC". This feature allows you to get a reading outdoors when the temp is between 50'F-86" (10'C-30'C). If you test outside of temp range your readings will become gradually more and more inaccurate. For best results, test indoors. No batteries necessary as you only need strong light - daylight (sunny or cloudy) or a lamp/flashlight. Brand New Professional Quality Salinity Refractometers with 35ppt Calibration Salinity Standard (3.6ml Vial) - Dual Scale 0-100 parts per thousand and 1.000-1.070 Salinity Specific Gravity. Each unit comes with a 5 year warranty. Reef shops welcome! We also carry the TRUE SALINITY REFRACTOMETER! The Reef Sea Meter is available at Amazon if you wish to have the best handheld unit available. Hard Case unit WITH 35ppt Salinity Calibration Standard - 3.6ml Vial Resale Quality - 50% heavier than the soft case cheap units Dual Salinity Scale - 0-100ppt 1.000-1070 Salinity SG Perfect for testing salinity Additional Details ------------------------------ Package quantity: 1