This refractometer offers an accurate, fast and easy-to-use method for testing engine coolant freeze point, glycol concentration and battery charge condition. It provides automatic temperature compensation for immediate and accurate readings of ethylene glycol or environmentally safe propylene glycol coolants with only a few drops of sample. Direct read scale provides readings in concentration or freeze point protection. Water Resistant. Specific gravity range from 1.100 to 1.400. Antifreeze protection from 0 to -48°C. Coolant concentration scale 0 to 70% (ethylene glycol) and 0 to 61% for propylene glycol. Refractive index range from 1.3330 to 1.4048. Warranty: 1 year.