RoamEO GPS Pet Location System, Large Collar Pet tracking system with Global Positioning System Receiver and collar Tracks pet within 1 mile range using GPS technology Track up to 3 pets with location, current movements, and velocity Includes waterproof GPS receiver collar and a tracking unit; no installation required Tracking unit measures 4-1/4 by 5-1/2 by 1-1/4 inches; 1-year warranty