Car enthusiasts and mechanics, this 4-in-1 refractometer is one of those tools you didn't know you needed but will use all the time! It measures four different automotive fluids with serious precision - the freezing point of both ethylene glycol and propylene glycol antifreeze (from -50°C to 0°C), specific gravity of battery acid (1.10 to 1.40 kg/l), windshield washer fluid freezing point (-40°C to 0°C), and even AdBlue urea concentration (30% to 35%). The Automatic Temperature Compensation (ATC) feature means you get accurate readings regardless of ambient temperature changes. Best part? It works with just ambient light - no batteries or power source needed! Made from aluminum and ABS rubber, it's portable and durable at just 155x40x40mm and 87g. Comes with a calibration screwdriver, 2ml jar, cleaning cloth, and plastic storage case. Whether you're maintaining your own vehicles or working professionally, this tool gives you quick, reliable readings to ensure your car's systems are in optimal condition. It's that kind of professional-grade tool that pays for itself by helping you prevent costly repairs and breakdowns from improper fluid mixtures.