Patented bottom platform features multiple rows of squeegee-like fins which easily dislodge stubborn dirt and debris. Cuts a 12" wide cleaning path and easily cleans gunite, fiberglass and vinyl surfaces in all types of inground pools. Features Exclusive SmartTrac programmed steering system maneuvers around tight corners, ladders, and obstacles to assure fast, thorough cleaning performance. It cleans faster than random-style cleaners reducing the possibility of missed spots Vac Port Door Fitting has a spring-loaded cover for added safety, and must be opened with a tool