SONIN Electronic Distance Measuring Tools send out narrow beams of sound waves that bounce off solid objects back to the hand-held receiver. Custom electronics and a microprocessor then convert elapsed time into a distance measurement and display it on the LCD. The Laser Targeting Range Finder adds a visible laser to assist the user in locating their target area. Built-in calculator to add linear measurements and compute areas and volumes. High visibility laser to show where you are aiming (for reference only). Measures from 16 inch Up To 60 Feet (18 meters). Displays measurements to the inch. Computes areas and volumes. Adds linear measurements, area, volumes. Measures in Ft/In, M/Cm, decimal Ft. and Yds. Tracking and Validate Modes. Can measure from top or bottom of unit. 7 memories with easy recall. Automatic internal temperature compensation. Auto shut-off 7 minutes after last use. Low Battery Warning. Requires One 9 Volt Battery (not included). Accuracy 99.5 percent +/- 1/4 inch(1cm). Protective pouch with belt loop. Recommended for indoor use only. One year warranty.