Figure 2. Schematic of the sequence of events during insertion of the glottic aperture seal (GAS) airway. (A) The curved retraction blade traps the epiglottis against the base of the tongue. The bodies of the cervical vertebrae are numbered. (B) The GAS airway is inserted so that the anterior surface of the foam cushion slides along the posterior surface of the curved retraction blade. (C) The GAS airway is advanced until firm resistance is encountered, at which point the distal end of the GAS airway has engaged the hypopharynx and the anterior surface of the proximal half of the foam cushion has been firmly pushed against the posterior surface of the curved retraction blade. (D) The curved retraction blade has been withdrawn, and the proximal half of the foam cushion, with the ventilation hole, is against and within the laryngeal inlet. The balloon has been partially inflated, pressing the GAS airway against the laryngeal inlet. Note that the proximal edge (tip) of the epiglottis is outside of (proximal to) the proximal end of the foam cushion.