The Blue Chewy Tube is smooth and is the largest and firmest of the Chewy Tubes. It is intended for adolescents and adults with developmental disabilities, autism or sensory integration disorders. It features a hollow stem of 5/8″ OD. Blue, smooth, extra-large-stemmed, T-shaped, tubular Teaches chewing and biting skills Can be used for eliminating teeth grinding and mouthing inappropriate items Reusable, durable and easy to clean Non-toxic, FDA compliant, free of latex, lead, PVC and phthalates