The ResMed HumidAire 4i Integrated Heated Humidifier for ResMed S8 and S8 II series CPAP machines is an improvement upon the HumidAire 3i in several ways. Specifically, the HumidAire 4i, also called the H4i, features:

• Larger water chamber
• Larger heating plate
• More robust design with a metal reinforcement in the front of the humidifier

• Fliptop lid design—no need to remove tube to refill water chamber. Convenient and user-friendly
• Compact design—unobtrusive in the bedroom and easily packed for travel
• Seamlessly integrated unit—simply snaps into place whenever required 385 ml capacity—high volume, high efficiency humidification in a compact unit
• Powered by ResMed’s S8 or S8 II devices—no additional power cords or cables required
• Dial control—easy to use in the dark and quick to respond
• Power-on light plus heating indicator—user-friendly
• Easy to clean—convenient