Genexice Robe Hook with Rotate & Lock Suction Cup Innovative rotate and lock suction technology that installs without the use of glue or tools Suction works on ceramic tile, glass, mirror, granite, stainless steel, acrylic and laminate surfaces Suction does NOT work on marble, porcelain, stone, dry painted wall, wood and any surface that is porous, bumpy, coarse, textured or matte finished Suction Cup Diameter: 2.5", Product Length: 4.5", Hook Depth: 1.5" Material: Chrome Plated Polyurethane