“…Our experience and the literature suggest that selection of the ETT types is important for successful tracheal intubation with the AWS, because the direction of ETT advancement from the guiding channel is defined by the configuration of the guiding channel and ETT angulation [2,5]. The direction of ETT advancement from the guiding channel differs between the different ETTs [6,7]. Also, the target mark was really designed for preformed curved polyvinyl chloride (PVC) ETTs.…”