VEE GEE® X-Series Handheld Refractometers are exceptionally simple to operate and provide quick, accurate measurements for the concentration of nearly any aqueous solution. Easy to Use. Operation consists of placing 1 or 2 drops of sample on the prism, closing the daylight plate over the sample, then looking through the focusable, cushioned-rubber eyepiece for the readings. Accurate. Featuring the largest, easiest-to-read scale available with clear, sharp figures, screen shading, and incredible contrast. These features significantly enhance overall accuracy even when several different operators use the instrument. All units feature rubber grips on the body, which block the transmission of hand heat to reduce temperature errors. Compact & Portable.