These MAY be used with GREAT CAUTION - if the surface is not perfectly smooth and clean, they can give way and cause a fall. For example, on out tile shower, the surface of the tiles curved near the edges, over time the suction cups would slip very slightly, and the bars would come loose. I might take one along on a trip as a precaution, but not rely on it full-time at home. Permanent grab bars are a better, safer option and not that expensive.