Baby helmet Size is adjustable Recommended age range is approximately 5 months to 3 years old. - Material: Mesh lining used - Size adjustment: Adjustable with Velcro - Washing instructions: Machine washable Thank you for looking. It was very useful for my twins who were learning to stand holding onto furniture and then walking on their own indoors. While there are signs of use due to washing, it has not been used many times and can still be used.