I have the Inogen Rav4 portable oxygen concentrator. For vehicles it has the standard plug in to a cigarette lighter. Problem is new vehicles replaced the cigarette lighter plug in on the dashboard to usb ports. I mentioned that fact to the Inogen sales rep who was interested in selling me this machine. She told me that all I needed was an adapter that had the male usb on one end and the female cigarette lighter plug on the other end and it would works just fine. I bought the machine based on it. Reality is I went through 10 of those adapters and not a single one worked. When you do a straight plug in to a cigarette lighter the cord works. I now have my health care worker taking both the Lexus and the portable oxygen concentrator machine to Auto Zone as they are advertising a 12 foot cigarette lighter extension to see it it will work since these engineers with PhD degrees designed the vehicle with a cigarette lighter plug in next to the tailgate of the SUV. Inogen support was a waste of time asking them questions.