Silicone and PP substance of superior quality and environmental friendliness. Damage-free, long-lasting, soft, non-toxic, adjustable, fits all Caution & RecommendationsThis item is not a toy and can not be used under parental supervision.The item cannot be washed in a machine. To clean, simply wash it with water or a soft soap and set it aside to dry in the shade.Hang it up for each use so that it does not come into contact with water for an extended period of time, which may degrade the stuff. Avoid rough edges and don't let your kid chew on it. If the product is defective, you should stop using it.