Hewitt's Airway This oropharyngeal airway as designed by Hewitt has two components: a metal collar component and the curved red India rubber tube, cut obliquely. They are joint together by a black string. It was used to overcome airway obstruction in unconscious patients during anaesthesia. The India rubber tube is stained because of use. The item appears as the fifth edition by Hewitt (1922), described as a ‘circular metal ring, with an internal diameter of half an inch, and a deep groove in its outer circumference to allow of the ring being held firmly by the teeth’. 1900-1949