Sealey-VS0052-Refractometer-Antifreeze-Battery-Fluid-Screenwash-Ad Blue-Sealey-VS0052-p-Accurately-measures-the-strength-of-battery-fluid-screenwash-antifreeze-&-Ad Blue-by-measuring-the-refractive-index-of-light-passing-through-the-mixture-Suitable-for-synthetic-antifreeze-mixtures-including-long-life-OAT-Organic-Acid-Technology-G13-&-aqueous-urea-content-of-Ad Blue-Temperature-corrected-prism-ensures-accuracy-Eyepiece-with-adjustable-focus-Simple-calibration-check-using-distil