See also:

Deactivating
Press and hold the closing button () in the tailgate until you hear two short tones. ...

Cleaning the steering wheel and gear or selector lever
•► Thoroughly wipe with a damp cloth or use leather care agents that have been recommended and approved by Mercedes- Benz. ...

Important safety notes
WARNING When leaving the vehicle, always remove the SmartKey from the ignition lock. Always take the SmartKey with you and lock the vehicle. Do not leave children unsupervised in the vehicle, ...