The Adtemp 421 measures a range from 89.6-108 degrees Fahrenheit or 32-42.2 degrees Celsius and features a fever alarm at 99.5 degrees Fahrenheit. Offers a compact ergonomic design that fits conveniently in your hand and is comfortable in the patient's ear. The probe cover free design is less costly and more convenient to use, simply clean with an alcohol prep pad. The Adtemp 421 features a 12-reading memory and a large 6 mm display, making it easy to read. Comes complete with a lithium battery, storage/travel case and operating instructions.