Ethylene Glycol: -50°C-0°C (0–70% ) Propylene Glycol : -50°C-0°C(0–70%) Resolution Factor: 5°C, 5%, (ATC) Temperature Compensation Range:10°C-30°C Field of View Description: Intermediate scale: (ETHYLENE GLYCOL) Ethylene glycol antifreeze freezing point. (PROPYLENE GLYCOL) Propylene glycol type antifreeze freezing point. Left scale: (BATTERY FLUID) Battery liquid specific gravity. 1.15 ~ 1.20 to be charged 1.20 ~ 1.25 power enough 1.25 ~ 1.30 sufficient power Right scale: glass cleaning solution freezing point First, the principle: The instrument can measure the antifreeze and glass cleaning agent freezing point, the proportion of lead-acid battery electrolyte. Temperature compensation device is included to ensure the measurement is simple and convenient, to ensure accurate measurement in the 10oC ~ 30oC ambient temperature. The basic principle is to use the total reflection critical angle method to measure the refractive index of the solution, and then calibrate the measured liquid concentration and its performance. Because of its principle of reliable, accurate to meet the actual needs, there are small size, light weight, handsome in appearance, easy to use, it is widely used in the automotive industry. 1, not in the relative humidity of more than 85% of the ring mirror in the long-term placement, so as not to affect the optical system. 2, do not get into the liquid and water adjustment knob and eyepiece, so as not to damage the internal components. 3, do not leap and collision, so as not to damage the instrument accuracy. 4, immediately after use with a clean cloth to the prism and the refractive plate wipe light net. 1)1 x Refractometer 2) 1 x pipette 3)1x instruction manual 4)1x mini screw driver 5)1x cleaning cloth Note : this product without retail box .