Suction cups are very strong when applied in the correct way to a suitable surface, suction cups need to be applied firmly when dry and will only stick to clean, dry glass type surfaces such as mirrors, flat none textured glass, bathroom tiles etc.
If the suction cup is struggling to stick after cleaning the surface it may need to be re moulded. To do this drop the suction cups into boiling hot water for 30 seconds and re shape into a cup, then allow to fully dry before re applying.
