Portable design & easy to use, with 5 clearly defined scales for the following 3 main uses:; 1. Measuring 1.10 to 1.40 kg/l specific gravity of battery acid and provide a quick reference of battery fluid condition (density of the electrolyte and each scale division corresponds to 0.01 g/cm3); 2. Measuring -50 ~ 0°C freezing point of automobile antifreeze based on ethylene glycol or propylene glycol.; 3. Measuring -40 ~ 0°C freezing point of windshield washer fluid based on ethanol or isopropyl alcohol; Auto temperature compensation (ATC), rest easy that your measurements are always accurate regardless of temperature variation