The Bushnell Yardage Pro Sport is the world's most simple to use, yet advanced laser rangefinder. Using Digital Technology and measuring a mere 3.9 x 3.1 x 1.7 inches, the 7.4 ounce Yardage Pro Sport delivers superb and accurate range performance to +/- one yard. Range to a deer or a golf flag as far as 200 yards out, or to a tree 450 yards away for a reference point. The single button operation allows outdoor enthusiasts to easily measure distance with confidence. The Yardage Pro Sport emits invisible, eye safe, infrared energy pulses. Sophisticated digital technology instantaneously calculates distances by measuring the time it takes for each pulse to travel from the rangefinder, to the target, and back. The ranging accuracy of the Yardage Pro Sport is plus or minus one yard / meter under most circumstances. The maximum range of the instrument depends on the reflectivity of the target. The maximum distance for most objects is 450 yards / 411 meters while for highly reflective objects the maximum is 800 yards / 732 meters. You will get both longer and shorter maximum distances depending on the reflective properties of the particular target and the environmental conditions at the time the distance of an object is being measured.