Installation points: Loosen the mounting head to lay the bottom silicone plate first, then firmly tighten or rotate the mounting head to deform the bottom silicone plate and fix it to the front protective cover. An arc-shaped void will be formed inside. Will be very strong at standard atmospheric pressure. When installing this product in an environment where the temperature is lower than 10, please soak the suction cup in boiling water for 3-5 minutes, then dry it and install it on a flat wall. Installation principle When the shower bracket rotates, the bottom of the thermos cup stretches out, and the protruding shape makes the cup generate strong air pressure, so that the cup is firmly fixed on the flat surface. Remarks Suction cups are suitable for surfaces Suction cups are suitable for: smooth tiles, glass, mirrors, metal panels, UV cured panels and other hard and smooth surfaces.