From the perspective of safety, when the helmet is strongly impacted, the soft foam spacer inside the helmet can prevent the impact from hurting the head. Some damaged helmets have three or four collision marks almost at the same place. As for the air permeability of the helmet, the ventilation device is not installed near the opening of the protective sleeve of the helmet itself, but on the protective sleeve body, mainly to maximize the protective range of the helmet in case of impact.

Some motorcycle helmets provide attached convenience devices, such as ventilation devices, face shields, ear protection devices, intercom devices, etc. Generally, it can be divided into winter helmet and summer helmet.