ClimateLine MAX Heated Tubing is designed for use with all S9 Series CPAP/BiLevel Machines that are equipped with an H5i Heated Humidifier. ClimateLine MAX uses built in sensors to increase temperature and humidity in the tubing while preventing condensation and rainout. ClimateLine MAX is slightly wider than standard ClimateLine Heated Tubing so it can support the higher pressure levels, up to 30 cm H2O, often used by BiLevel therapy users.