The 421D Laser Distance Meter's features include audible feedback for taking room angle and incremental measurements, a +/- 45 o tilt sensor for taking indirect measurements in hard-to-reach areas and enhanced Pythagoras calculation for indirectly determining distance. The instrument automatically stores the last 20 measurements for quick recall of previous measurements. The unit has a bright laser for easy targeting and large liquid crystal display. Buttons are positioned for one-hand operation. An automatic shut-off feature improves battery life, providing up to 5000 readings from a pair of AAA batteries. It is IP54 rated for resistance to water spray and dust.