The Zen-O DC power supply enhances the freedom and independence your portable oxygen concentrator provides you with. Whether you're in between errands, taking a road trip, or going on a date with your loved one, the DC power supply will allow your concentrator to supply you with oxygen while preserving your battery life for when it really matters. The DC power supply plugs into any 12v outlet or cigarette lighter in your vehicle, and you can use it in your car, truck, RV, or boat. Whenever your Zen-O is plugged into the DC power supply, not only will your concentrator run off of your vehicle's battery, the batteries you have installed in the machine will recharge on EVERY oxygen setting—it doesn't matter if you require 2.0 LPM or a pulse flow setting of 6. The major advantage is that you can recharge your batteries virtually anywhere as long as your vehicle has a 12v outlet. The DC power supply also has the ability to recharge one or two batteries as long as they are installed in the machine. It's important to remember that because the DC power supply uses your vehicle's battery, it will take longer to fully recharge than the AC power supply.