Sealey Ethylene Glycol Antifreeze Tester Disc Type AK4120Checks condition of coolant antifreeze, hot or cold. Freeze protection level is indicated by the number of the six large coloured discs which float in the sample. Easy to read temperature table on the virtually unbreakable plastic body. Freeze protection level is indicated by the number of the six large coloured discs which float in the sample. Easy to read temperature table on the virtually unbreakable plastic body. Specifications Detail Checks