The new M-Class features an extremely sturdy passenger cell that protects the occupants by virtue of its energy-absorbing front-end structure, reinforced doors, extended crumple zones and raised ride position. There are also multi-stage airbags and the new NECK-PRO head restraints (available as China standard equipment for ML 500 4MATIC). Following an impact from the rear that exceeds a predefined threshold, the front head restraints move towards the occupants' head, preventing the risk of whiplash injuries.