Schuberth has been equipping their helmets with the Anti Roll-Off System (AROS) for quite some time. The AROS is an important addition to the motorcycle helmet because it will not allow the properly locked-in helmet to roll off the wearer’s head.
While the chin strap secures the helmet in place and will oppose any lift action, the same does not apply to other helmets. The ECE testing standards require that a properly locked helmet does not pivot forward more than 30 degrees.
Limiting the pivoting action significantly reduces injuries. Schuberth’s AROS helmets come with dual extra straps linking the rear portion of the shell to the chin straps, reducing the freedom of movement in case the helmet is pulled towards the front.
ECE tests have to be made with a 10kg (22 lbs) weight attached to the back of the helmet and dropped from a height of 75cm (29”). The forward pivoting is restricted to 15 degrees on AROS helmets, making them much more secure.
https://www.autoevolution.com/news/schuberth-s-aros-system-brief-explanation-54780.html