A protective helmet (1) comprising a cap (2) having a rear portion on which an aerodynamic deflector (3) is mounted, the protective helmet (1) being characterised in that at least one aerodynamic flap (4) is mounted so as to move freely on the aerodynamic deflector (3) in order to be able to be deployed by aerodynamic forces generated by an air flow. A favoured, non-limiting use of the invention is in the field of motorbike racing.

A helmet according to one embodiment of the present disclosure includes a shell in which a space where the head of a user is placed is formed and a shield rotatably provided to the helmet and having a first protruding part formed to protrude from both ends.

A protective helmet adapted to be worn by a user and to protect the head of the user against impacts, such a protective helmet including a rigid outer shell delimiting an inner space designed for housing the head of user, at least one appendage attached to the outer shell and attachment means for attaching the at least one appendage to the outer shell. The attachment means are adapted to removably attach the at least one appendage to the outer shell and include a plurality of male connectors and a plurality of female connectors, each female connector including an inner housing for the respective male connector.