The Sealey AK4120 is an ethylene glycol antifreeze tester designed for checking the condition and protection level of engine coolant in both hot and cold conditions. This simple yet effective tool uses a hydrometer-style design with six large coloured discs that float in the coolant sample to indicate the freeze protection level. The tester features a tough, virtually unbreakable plastic body with an easy-to-read temperature table printed directly on the unit, allowing mechanics and vehicle technicians to quickly assess coolant strength without complex calculations or external reference charts. Simply draw a sample of coolant into the tester and count the number of floating discs to determine the protection level. Ideal for vehicle servicing workshops, mobile mechanics, and automotive maintenance professionals who need to verify coolant concentration during routine servicing or winter preparation. The lightweight design and durable construction make this tester suitable for regular use