The General LD50 Base Station Lightening Detector Used by Little League teams, golf courses, farmers, construction sites, schools and universities, athletic complexes and other recreational districts. This portable/ground-based unit comes in a rugged, weather-resistant plastic case and is more powerful than the personal unit and will detect storms within 40 miles but will start detecting thunderstorms up to 70 miles away. It will also sense if the storm is moving towards, away, or parallel to your location. It will identify severe thunderstorms as well as storms that can produce dangerous winds, heavy rains or tornadoes. It is battery operated and can be hand-held or table/wall mountable. It measures 6 x 3.1" x 1.5" and weighs 10.8 oz. (w/o batteries). The LED s indicate ranges from 0-3 miles, 3-8 miles, 8-20 miles and 20-40 miles and the number of alarm beeps will indicate the proximity of lightning.