Ardi 2.4GHz Digital RF Guardian Angel, 807G1, 1 Base Unit & 1 Tag Unit. Kid Tracker/Smart Direction & Distance Indicator/500M Effective Distance/Proximity Alarm Function/Mute Mode. Made in Taiwan 1,600 feet search radius (*Distance varies depending on terrain and other factors) The alarm can be set the distances from 16feet, 32feet, or 64 feet (*Distance varies depending on terrain and other factors) Tags can transmit Panic/Stress button to the base unit. Alert modes 95dB alarm and vibration. One base controls up to four tags. The base is equipped with direction indicator to speed the search. Both base and tag can be muted while you are searching each other. Works indoors and outdoors. No assembly or installation needed. Light and weight easy to use