Applying/releasing the electric parking brake manually
WARNING Risk of accident and injury due to children left unattended in the vehicle
If children are left unattended in the vehicle, they could:
Open doors, thereby endangering other persons or road users.
Get out and be struck by oncoming traffic.
Operate vehicle equipment and become trapped, for example.
In addition, the children could also set the vehicle in motion, for example by:
Releasing the parking brake.
Changing the transmission position.
Starting the vehicle.
Never leave children unattended in the vehicle.
When leaving the vehicle, always take the key with you and lock the vehicle.
Keep the vehicle key out of reach of children.
This also applies to the Digital Vehicle Key if the "Digital Vehicle Key" function is activated via Mercedes me connect.
Applying
Push handle 
.
. The red 
indicator lamp appears in the instrument cluster.
The electric parking brake is only securely applied if the indicator lamp is lit continuously.
Releasing
Switch on the ignition.
Pull handle .
. The red indicator lamp in the instrument cluster goes out.