This travel DC power converter enables the ResMed S9 Series CPAP to use DC power from an accessory port in a car or boat, or from a battery.
This converter is approved to use the humidifier of your CPAP machine. It is the only power converter for ResMed that supports this option.
**Includes alligator clip adapter for direct connection to a battery.
**The adapter includes an on/off switch. Before plugging into a DC power source, be sure the switch is in the OFF position. After connection turn to ON to power your machine.