Real Instruments EHS-10 Manual Handheld Refractometer

This dual scale salinity refractometer is used to measure, monitor and control the concentration of salt water and brine, especially useful for aquarium and marine applications. This high quality refractometer measures on 2 scales, specific gravity (D 20/20) and parts per thousand and replaces your poor quality and difficult to read hydrometer. With just a couple of drops of aquarium water you know exactly what your salinity is.