Glycol antifreeze freezing point: -50 ~ 0 °C, division value of 1 °C Freezing point of the propylene glycol antifreeze: -50 ~ 0 °C, division value of 1 °C Specific weight of the electrolyte: 1.10–1.40, index value 0.01 (1.15 ~ 1.20 needs charging; 1.20 ~ 1.25 sufficient power; 1.25 ~ 1.30 sufficient power) Glass cleaning fluid freezing point: -40 ~ 0 °C, division value of 5 °C Contains: 1 x refractometer 1 x screwdriver 1 x manual 1 x cleaning cloth 1. USE: This refractometer allows measurement of ethylene glycol and propylene glycol concentration in antifreeze for vehicles, solar systems, heat pumps, windshield washer fluid, heating systems, and other machinery or systems. It also measures freezing point and specific gravity of various liquids. 2. MEASURING RANGE: Ethylene glycol: -50°C to 0°C Propylene glycol: -50°C to 0°C Windshield washer fluid (ethanol + water): -40°C to 0°C Propylene glycol + water (SRF1): -40°C to 0°C Urea concentration: 30% – 35% Battery acid: 1.10 – 1.40 kg/L 3. TEMPERATURE COMPENSATION: Built-in automatic temperature compensation ensures accurate and reliable readings under varying ambient temperatures. PRECISION MEASUREMENT: Features an adjustable eyepiece with 4–8x magnification and stepless manual focus, suitable for all users. 4. HIGH QUALITY: Chrome-plated brass body provides excellent resistance to chemical corrosion and wear, significantly extending the lifespan compared to aluminum housings.