Refractometer is a precision aquarium testing tool used to accurately measure salinity and specific gravity in marine and reef aquariums. Designed for reliability and ease of use, this essential device provides quick and accurate readings to help maintain stable water parameters for corals, fish, and marine invertebrates. Ideal for saltwater aquariums, reef tanks, and aquaculture setups, a refractometer ensures proper salinity levels for optimal coral health and system stability. Built with high-quality optics and durable construction, it offers consistent performance and is a must-have tool for monitoring and maintaining a healthy marine aquarium environment.