?? NOTE, The mounting surface must be flat, smooth and non-porous. For tile wall application, they only work on glazed tiles (size > 4x4"). Make sure there's no texture on the shower wall. ?? NO TOOL REQUIRED INSTALLATION, These suction grab bars are easy to install, tool-free/no drilling. They are easy to release as well, so you can bring them on travel. ?? SAFER TO USE, The indicators will change from red to green when a safe and secure hold is achieved. Before each use, test the firm hold of the suction device. Ensure that both indicators are green. If the adhesion seems insufficient, release the suction assist bar and reattach again. ?? PERFECTLY FOR ALL AGES, This could be a warm gift for elderly parents/grand parents or friends. It's sweet to prepare one for senior/old visitors that need balance assist in shower. And it's portable for travel use where the place you stay don't have safety grab bars. Can also be used as a handle on fridge panels or glass doors. ?? ONE-YEAR WARRANTY, These AquaChase Suction Grab Bars come with a one-year warranty against any manufacturing defects.