See also:

Activation conditions
You can activate the HOLD function if: Rthe vehicle is stationary. Rthe engine is running. Rthe driver's door is closed or if your seat belt is fastened. Rthe electric parking brake is released. ...

NECK-PRO head restraints/NECKPRO luxury head restraints (except AMG vehicles)
NECK-PRO head restraints/NECK-PRO luxury head restraints increase protection of the driver's and front-passenger's head and neck. In the event of a rear collision of a certain severity, the NE ...

Removing the mechanical key
Push release catch 1 in the direction of the arrow and at the same time, remove mechanical key 2 from the SmartKey. ...