See also:

General notes
USA only: This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: 1. This device may not cause harmful interference, and 2. this device must ...

Mercedes-Benz M-Class Owners Manual
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Points to observe before use
The sockets can be used for accessories, e.g. lamps or mobile phone chargers with a maximum current draw of 180 W (15 A). If you use the sockets for long periods when the engine is switched off, th ...