Fish tank hydrometer: 💧💧💧— refractometer：this refractometer measure salt water or of water, ideal for aquariums and marine monitoring.
Aquarium test tool: 💧💧💧—made of sturdy plastic, glass material, lightweight and durable, with excellent texture. you can test your marine aquariums salt level, provide an accurate test result.
Professional refractometer: it is widely applied in sea water, aquarium, swimming pool, etc.