The most compact Tympanic thermometer on the market. The Adtemp 421 Thermometer features measures core temperature instantly from the ear reliably and accurately. Range 89.6°F-108°F - .4°F or 32°C-42.2°C - .2°C depending on scale selection. Probe-cover-free design is less costly and more convenient to use. Large 6mm illuminated display is easy to read. Compact (5" Long, 1.9 oz.) ergonomic design fits comfortably in operator?s hand and patient's ear. Audible fever alarm at 99.5°F (37.5°C). 12 reading memory. Complete with Lithium battery, storage/travel case, and operating instructions.