VEVOR Car Refrigerator, 12 Volt Car Refrigerator Fridge, 50 L Single Zone Portable Freezer with Wheels and Handle, -4℉-68℉, 12/24V DC and 100-240V AC Compressor Cooler for Outdoor, Camping

Does this actively cool only while plugged in or does it also have a battery it is able to cool with? And if it does havea battery, what is the capacity?