The Red Sea Seawater Refractometer is a precision instrument designed specifically for accurately measuring salinity in marine and reef aquariums. Calibrated for natural seawater rather than brine, it delivers highly reliable readings of specific gravity and salinity, ensuring optimal conditions for corals, fish, and invertebrates. Its clear scale, durable optical lens, and automatic temperature compensation provide consistent accuracy, while the sturdy construction ensures long-term dependability. Easy to calibrate and simple to use, the Red Sea Seawater Refractometer is an essential tool for maintaining stable, reef-safe water parameters and supporting the health of sensitive marine life.