Mc520 instant ear thermometer responds in just 1 second fast small lightweight ear thermometer takes 250 scanssecond memory feature recalls last temperature reading too measures in either fahrenheit or centigrade beeps once to indicate correct positioning and 4 times for measurement completion auto shutoff extends battery life storage case keeps thermometer and lens covers together operates on one dc3v lithium battery battery is included and lasts for approximately 2000 measurementsfe