Features: High precise salinity refractometer for seawater aquaculture ensures optimal water environment with ±0.1% accuracy, featuring automatic temperature compensation (0-30℃) and corrosions resistant aluminum alloy construction for efficient saltwater testing. Equipped with oversized 1mm wider eyepiece for clearer visibility and builtin temperature compensation technology that eliminates manual adjustment, this saltwater aquarium salinity tester maintains accuracy across varying environmental condition. Great for marine biologists, professional aquarium operators, and home aquarists maintaining reef tanks or saltwater ecosystem requiring precise salinity monitoring between 25 50‰ concentration levels. Essential for routine water quality check in marine habitats, aquaculture farms, or home saltwater aquariums to prevent stress in fish and corals species caused by salinity fluctuation. This multifunctional aquarium water testing tool combine better clear with aluminum alloy housing, featuring easy to read scale and calibration systems that simplifies maintenances of optimal salinity levels in marine environment. Specifications: Component: Aluminium Alloy Product Size: Approx. 20x5x8cm/7.87x1.97x3.15inch Package Includes: 1 Set Salinity Refractometer note: Please allow 0-1cm error due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual color the item.