I purchased these a long time ago but like other reviewers have found they don't actually stick to some tiles. However not to be outdone I stuck it to the outside of the glass shower door instead, still no permanent suction. I wet it, I pushed it, I concentrated on the middle and edges as recommended but the edges just curled outward and down it came again. My husband lost patience with it as razor holder and threw it out. Maybe if they were thinner better suction could be achieved because they are a decent size hook. Disappointing OXO product as they are usually so reliable.