Reliable quality， shipped fully tested and calibrated
Large LCD screen， convenient for check and record
Long battery life， include 9V carbon zic battery
K sensor allows HT-81 to measure air temperature in Celsius or Fahrenheit units
Measures air velocity in five units: feet per minute ( ft / min )， meters per second ( m / sec )， miles per hour ( MPH )， kilometers per hour ( km / hr ) and nautical miles per hour ( knots )