Callaway 300 Laser Golf Rangefinder Range 5-1000 yards with 6X magnification (+/- 1 yard accuracy), Includes CR2 3V battery and carry case; Pin Acquisition Technology (P.A.T) locks onto flag quickly from up to 300 yards Scan landscape to acquire distances to multiple targets at once Lightweight (7.5 oz.), compact design; water/fog proof, legal for tournament play. Please refer the User Manual/ Trouble Shooting Steps under product details