The NAR Esophageal Detection Device (EDD) is a disposable tool used to verify proper endotracheal tube placement by utilizing the anatomical differences between the trachea and esophagus. Because the trachea has cartilaginous rings, it is a rigid structure. As vacuum is applied the device will refill easily if the ET tube is in the trachea. If the ET tube is in the esophagus, the device will not retract because the esophagus will have collapsed against the distal end of the ET tube.