These handheld measuring devices use ultrasound technology to accurately measure distances (99.5% ± ¼” (1 cm)) at both indoor and outdoor crime scenes. Both of these devices work by sending out narrow beams of sound waves that bounce off solid “targets” and return to the handheld receivers. The receivers contain sophisticated electronics and microprocessors that convert elapsed time into a distance measurement which is shown in the easy-to-read LED display window. Both devices have a built-in calculator to add linear measurements and compute areas and volumes. Easy to understand instruction sheets are also included. Reorder Number EDMD (red) is equipped with a laser pointer to show you where you are aiming; however, it can only be used when the “target” is a flat surface, such as a wall or window. If the target is not flat, such as a tree trunk, light pole, etc., the sound waves may not return to the receiver. Features Reorder Number EDMD Red: • High visibility aiming laser • Measures from 1'6" up to 60' (18 m) Common Features: • Computes areas and volumes • Adds linear measurements, area, volumes • Measures in ft./in., m/cm, decimal ft. and yds. • Tracking and validate modes • 7 memory with easy recall • Automatic internal temperature compensation • Auto shut-off 7 minutes after last use • Multilingual Quick Reference instruction label • Low battery warning • Powered by two 9 volt batteries (not included) • Accuracy of 99.5% ± ¼" (1 cm) • Protective pouch with belt loop • One-year warranty