A helmet is disclosed having a padding element removably constrained to the shell and provided with a first seat so that a first protrusion integral with the shell is reversibly engaged, reversible male-female coupling members to reversibly couple the shell and the padding element, which are adapted to define a hinge point for the relative rotation between the shell and the padding element. The helmet has restraining members to selectively restrain and release the first protrusion in and from the first seat. The restraining members are movable between a first restraint position to restrain the first protrusion in the first seat, so that the relative rotation between the shell and the padding element is prevented. A second disengagement position of the first protrusion from the first seat is also provided so that the relative rotation between the shell and the padding element is allowed.