The SpeedTrac Speed Sports Radar Detector is perfect for recording speeds in baseball, soccer, tennis, hockey, golf, karting, football, cricket, running, skiing, racquetball, field hockey, and more. The radar does not need to be hand-held during operation. It records speeds up to 150 mph and works at a distance of approximately 60 feet. The weather resistant housing allows safe outdoor use. Operates on 4 "C" batteries (not included) or an optional 6 volt AC Adapter. IMPORTANT: The prior SpeedCheck 8 volt A/C Adapter is not to be used with this unit! All electronics are warrantied from the date of purchase by the manufacturer only. Each unit is triple tested on the assembly line of manufacturer. Due to their surface material, tennis and vinyl coated balls may sometimes give missed or inaccurate readings. Increased accuracy and reduced ghosting is obtained by placing the unit at least 15 ft. away from the subject.