Breathing tube assemblies for use with a respiratory therapy device, such as a continuous positive airway pressure (CPAP) device, includes an elbow that permits adjustment of a position of the breathing tube assembly relative to the respiratory therapy device. In some arrangements, the breathing tube assembly includes a breathing tube and a swivel elbow. The breathing tube is rotationally fixed relative to the respiratory therapy device and the swivel elbow rotatable relative to the breathing tube. In other arrangements, the breathing tube assembly includes an elbow that can be coupled to the respiratory therapy device in one of several possible positions.