I bought one of these on sellout.woot a couple weeks back. I haven’t used it yet but it sure looks shiny and the instructions were helpfully in many different languages.
Continuous power up to 400W with Battery Cables and Clips
Continuous power up to 80W with 12V DC Plug
If you want to just plug this into your lighter socket/power port, it only provides 80 watts. To really take advantage of this you either have to open the hod and clamp the cables to your battery, or have a spare 12 volt battery on hand…