Grand Index Salinity Aquarium Refractometer Rhs-10atc with Blue Rubber ,Great for Aquarium Tool & Marine Fishery Measuring Range:Salinity: 0-10% ; Refractive Index: 1.000-1.070 Material:Aluminum alloy hand held,easy to carry Great for Aquarium Tool & marine fishery salinity measurement Packing included:Pipette * Operations manual * Mini-screw driver * Soft protective carrying case