This Draper expert quality, precision refractometer is suitable for measuring Urea concentration in Ad Blue diesel exhaust fluid as well as measuring the strength of anti-freeze. Accuracy is ensured thanks to this models focusable eyepiece & Automatic Temperature Corrected prism. This model is designed to be used with standard ethylene glycol & propylene anti-freeze. The product comes packed in a storage case & is supplied with a calibration screwdriver, a calibration fluid, a pipette & also a cleaning cloth.