The Tube Pantos is eye-catching with its round frame. It uses a flexible form-fitting material that can be stretched or tightened according to your head size. Unique in its kind, it can stretch nearly 11 inches and with a closed diameter of about 7 inches. It is an inventive modification on the original product customers have loved for decades. The Tube product is for everyone, for all head sizes and adjustable to fit your unique needs.