A clever question! Water is an unwelcome guest that can enter your home through the front door or secondary entrances. Only Rapid manufactures all the flood-prevention safety devices that block water from entering your home through: floor drains, air vents, outdoor electrical outlets, plumbing fixtures (toilet, bathtub, bidet, sink, shower drains); crawl spaces, through basement access grates, basement access windows, basement windows, garage ramps, vehicle and pedestrian gates, etc., etc. This is because water can also enter rooms through backflow, back pressure in the sewer system, or simply due to the basic “principle of communicating vessels.”