Feature - Color: As Shown. - Material: Aluminum+Rubber. - Size: 17 x 4 x 4cm. - Measuring Range: ethylene glycol: 50 and degree; c - 0, level c propylene glycol: 50 and degree; c - 0, level c cleaning agents: 40 and degree; c - 0, level c Battery liquid: 1.100-1.400sg - Resolution Factor: ethylene glycol: 5 and degree; c propylene glycol: 5 and degree; c cleaning agents: 10 u. degrees c battery liquids: 0.01sg - (ATC) Temperature compensation range: 10 u. Grad; c- 30 u. Grad; c - Accurate measurement based on good calibration, please calibrate the refractometer before your first use. But you don't have to calibrate it frequently, once every a few months is OK. When you put your sample to be tested on the daylight plate, make sure the liquid spreads across the entire surface of the without air bubbles or dry spots. - Clean the instrument with a cloth after each use, keep the refractometer dry and clean, which will keep the instrument accurate and durable. Do not put the entire instrument into water to wash, this may lead the refractometer to be foggy or rusty inside. Please do not loose any connection part, and dont dropping, colliding, shaking the instrument intensely. - Models are equipped with such degrees c unit. with the indication of the percentage we know of either ethylene glycol or propylene glycol cooling freezing. - You can also used to test the concentration of ethylene glycol or propylene glycol in antifreeze liquids. - There is also an additional scale for measuring the freezing point of the windscreen cleaning fluid. - It is fully equipped with atc, which automatically adapts to correct temperature discrepancies during the use.