If you connect it to 12v battery directly, you will need this one. With/without Humidifier. This is only for Philips Respironics Dreamstation CPAP machines. This 12 Volt DC Power Cable System is compatible with the following Machines: DreamStation CPAP DreamStation PRO CPAP DreamStation Auto CPAP DreamStation BiPAP Pro DreamStation BiPAP Auto
With the battery connection.