Standard equipment for the CLS includes two-stage front airbags, sidebags in the   front and windowbags. Sidebags in the rear doors are available as an option. 
                    
                    In the event of a side-on collision, the sidebags and windowbags on the   impact side are able to deploy simultaneously after a pre-defined severity of   impact. The windowbags unfold like an inflatable curtain between the A and C   pillars, offering additional head protection for passengers in front and rear.   The front airbags are activated in two stages, depending on the severity of a   possible frontal collision.
                    
                    In addition, the restraint system is fitted   with satellite sensors in the radiator area that can operate in conjunction with   the crash sensor in the centre console to determine the strength of a frontal   collision more precisely and more quickly.
                    
                    Automatic child seat   recognition, which is available as an option, prevents the front airbag from   deploying if a Mercedes-Benz child seat with transponder is fitted on the front   passenger seat. Belt tensioner and sidebag remain active in order to protect the   young seat occupant.
                    
                    All the seats are fitted with a 3-point seat belt   and head restraint. The front seats feature crash-responsive NECK-PRO head   restraints. During a rear-end collision these can move forwards and up by sensor   control, so potentially considerably reducing the whipping motion of the   head.
                    
                    Belt tensioners on the front and rear seats pull the belts taut   against the body in the event of a frontal or rear-end collision of a specific   severity. The belt force limiters (adaptive in the front) increase occupant   safety in a frontal collision, since they can ensure that the tension is   released in a controlled manner once a set limit has been reached.
                    
                  An   additional roll-over sensor in the airbag control unit triggers all of the belt   tensioners and both windowbags in certain roll-over situations.