The PR System One REMstar BiPAP AVAPS Machine comes standard with carrying case, bag, memory card, manuals and now comes packaged with the Respironics Performance Tubing. System One Humidity Control (Optional) The PR CPAP humidifier and water chamber design are breakthroughs for managing rain-out and water damage. System One Humidity Control technology analyzes ambient temperature and patient airflow to reach relative humidity at the mask. Choose from 5 levels of relative humidity. System One is the first humidifier in the industry which accounts for room humidity. Sensors, inside and outside the CPAP machine, closely monitor changes in humidity and help to prevent condensation from forming inside the tube. Dry Box technology is another breakthrough in reducing water damage to the CPAP. Several unique designs are incorporated into the humidifier to prevent water from exiting the chamber. To start, the air outlet port has been moved from the side of the humidifier onto the top. This centers the entire delivery; minimizing the total water displacement around the hole. The water chamber is outfitted with one-way valve, between the machine and the humidifier. Any water that manages to escape the chamber gets trapped within the Dry Box, which acts as a reservoir for any water ingress past the valve. System One and Dry Box Technology make it possible for the Respironics machines to be truly spill-free. This humidifier, even with a chamber filled to the "Full" indicator line, can be tilted, shaken, and even turned upside down without water leaking back into the device. Digital Auto-Trak Algorithm and Bi-Flex Technology Digital Auto-Trak Sensitivity is the brains behind Respironics' Flex Technology and AVAPS feature. A patented algorithm monitors breathing patterns and responds to abnormal pressure changes. The Auto-Trak system measures variable triggers and cycle thresholds, then adjusts pressure automatically to provide effective sleep therapy. The Digital Auto-Trak components are always active and the system reacts to the first component that detects a change in sleep, providing maximum sensitivity.