Flexible, comfortably padded and easy to fit, the Headmaster Collar is available in six different sizes from infant to large adult.This model is designed to fit children with a chin-to-jaw measurement of 7.5cm (3\"). It helps to keep the head in the correct position but it will also allow for movement of the neck, both extension and flexion. It attaches securely around the back of the neck using an adjustable strap, leaving the front open. Consequently, it will allow access for a tracheal tube if required.