No suction cups, adhesives or wall mounts are needed, and it won't leave any residue behind. The silicone SUDSKI securely grips to glossy surfaces like glass, mirror, marble, metal, shiny tiles, and laminate using a patented technology. Revolutionary space-age drainage system. Please note: This product is not intended for use on stone and other unglazed tiles. Grip works best on smooth, glass-like surfaces. Do not use with glass.. See full description for further details