Oral or oropharyngeal airways are rigid plastic tubes which are shaped according to the outline of the hard and soft palate, against which they sit inside the mouth if placed correctly. They have a flange that should rest against the patient's lips and prevent the device from being inserted too deeply into the mouth. Most manufacturers adhere to a standardized color-coding system of sizes. The typical adult sizes are green, yellow, and red by increasing size.
These devices are used to help with creating and mainaining a patent upper airway, often in conjunction with the basic airway maneuvers.
Chosing the correct size and insertion of oropharyngeal airways is descibed in the 'basic airway maneuvers' article.