Sealey AK4123 Ethylene Glycol Antifreeze Pocket Tester Ball Type Convenient, pocket sized tester for ethylene glycol antifreeze mixtures. Freeze protection level is indicated by the number of coloured balls which float in the sample. Easy-to-read temperature table on the body. Convenient, pocket sized tester for ethylene glycol antifreeze mixtures Freeze protection level indicated by the number of coloured balls which float Easy-to-read temperature table on the body Model No AK4123