That works very well in practice: Thermometer turn on, press the button, insert thermometer into the ear, press the button and wait for about 2 seconds. Done. Toll!
Unfortunately, the measurement accuracy is completely inadequate: Repeated measurements in the same ear is a deviation of 0.5 degrees is not unusual. A deviation of up may be to a degree between both ears.
In comparison, at the rectal measurement with a digital thermometer is rarely a deviation of 0.1 degrees to see mostly the result is identical.
Some reviews report very accurate measurement results, while others have made similar observations as I do. I conclude that the variation within the series is quite high, so a classic quality problem.
My recommendation: buy and try immediately. If it is too imprecise send back. Repeat the process until a is "good" copy here.