<qa>  What is the esophageal tracheal combitube?The esophageal tracheal combitube ETC was first marketed in 1987 by Frass, Frenzer, and Zahler as an alternative airway to traditional endotracheal intubation. The combitube is a polyvinyl chloride double lumen supraglottic airway that can be placed blindly, quickly, and with minimal training. The device is available in two sizes, 37F for small adults 4-6 feet tall and 41F for larger adults up to 198 cm height. It is now widely used in Wisconsin for the pre-hospital airway management algorithm for trauma patients. 