Red Sea Seawater Salinity Refractometer DEF and then place the acrylic

and then place the acrylic block on top and you are on your way

00              REST OF THE WORLD: $15

The auto shut-off feature assures the battery life will not be drained if you forget to turn it off

produce alcohol

Red Sea Seawater Salinity Refractometer DEF and then place the acrylicRed Sea Seawater Refractometer Product #: RED R12018 REFURBISHED and have A FULL 3 YEAR WARRANTY! Red Seas Seawater Refractometer offers exceptional accuracy, for measuring the absolute salinity of seawater at a temperature of 25oC 77 0F. Most refractometers used within the aquarium hobby are not specifically designed for reef aquariums and use an algorithm for the measurement of brine (NaCl rather than seawater) and at a temperature of 15oC 59 0F