Up for auction is one brand new: Extech RF Series Portable Refractometer Model# RF18 0 to 18% Brix Refractometer Measure the concentration of sugar, salt, lubricants, antifreeze, cutting fluids & more The Extech RF series portable refractometers are easy to operate, provide accurate and repeatable measurements on easy to read scales. Automatic temperature compensation models are available for sugar, salt, lubricants, cutting fluids and antifreeze. Requires only 2 or 3 drops of solution.