A protective helmet comprising - a curved helmet shell, - a supporting structure (3, 4.1, 4.r, 5, 6, 8, 10), - internal equipment and - at least two connection units, wherein the protective helmet is configured such that the internal equipment comes into contact with the head of a wearer of the protective helmet, wherein the supporting structure (3, 4.1, 4.r, 5, 6, 8, 10) - is fixed to the inside of the helmet shell and - is configured to support the internal equipment, wherein each connection unit is configured to connect the internal equipment detachably to the supporting structure (3, 4.1, 4.r, 5, 6, 8, 10), wherein each connection unit respectively comprises - a component (14.1,..., 15.1,..., 16.1,...) on the supporting structure side which belongs to the supporting structure (3, 4.1, 4.r, 5, 6, 8, 10), and - a component (11.1,..., 12.1,..., 17.1,...) on the internal equipment side which belongs to the internal equipment, wherein each component (14.1,..., 15.1,..., 16.1,...) on the supporting structure side and each component (11.1,..., 12.1,..., 17.1,...) on the internal equipment side belongs to exactly one connection type, characterized in that the protective helmet has at least two different connection types, wherein a component (14.1,..., 15.1,..., 16.1,...) on the supporting structure side can then be connected to a component (11.1,..., 12.1,..., 17.1,...) on the internal equipment side in order to produce a detachable connection between the supporting structure (3, 4.1, 4.r, 5, 6, 8, 10) and the internal equipment if the two components belong to the same connection type, and wherein a component on the supporting structure side cannot be connected to a component on the internal equipment side or the two components are not able to produce any connection between the supporting structure (3, 4.1, 4.r, 5, 6, 8, 10) and the internal equipment if the two components belong to two different connection types. - a curved helmet shell, - a supporting structure (3, 4.1, 4.r, 5, 6, 8, 10), - internal equipment and - at least two connection units, wherein the protective helmet is configured such that the internal equipment comes into contact with the head of a wearer of the protective helmet, wherein the supporting structure (3, 4.1, 4.r, 5, 6, 8, 10) wherein the protective helmet is configured such that the internal equipment comes into contact with the head of a wearer of the protective helmet, wherein the supporting structure (3, 4.1, 4.r, 5, 6, 8, 10) - is fixed to the inside of the helmet shell and - is configured to support the internal equipment, wherein each connection unit is configured to connect the internal equipment detachably to the supporting structure (3, 4.1, 4.r, 5, 6, 8, 10), wherein each connection unit respectively comprises wherein each connection unit is configured to connect the internal equipment detachably to the supporting structure (3, 4.1, 4.r, 5, 6, 8, 10), wherein each connection unit respectively comprises - a component (14.1,..., 15.1,..., 16.1,...) on the supporting structure side which belongs to the supporting structure (3, 4.1, 4.r, 5, 6, 8, 10), and - a component (11.1,..., 12.1,..., 17.1,...) on the internal equipment side which belongs to the internal equipment, wherein each component (14.1,..., 15.1,..., 16.1,...) on the supporting structure side and each component (11.1,..., 12.1,..., 17.1,...) on the internal equipment side belongs to exactly one connection type, characterized in that the protective helmet has at least two different connection types, wherein a component (14.1,..., 15.1,..., 16.1,...) on the supporting structure side can then be connected to a component (11.1,..., 12.1,..., 17.1,...) on the internal equipment side in order to produce a detachable connection between the supporting structure (3, 4.1, 4.r, 5, 6, 8, 10) and the internal equipment if the two components belong to the same connection type, and wherein a component on the supporting structure side cannot be connected to a component on the internal equipment side or the two components are not able to produce any connection between the supporting structure (3, 4.1, 4.r, 5, 6, 8, 10) and the internal equipment if the two components belong to two different connection types. wherein each component (14.1,..., 15.1,..., 16.1,...) on the supporting structure side and each component (11.1,..., 12.1,..., 17.1,...) on the internal equipment side belongs to exactly one connection type, characterized in that the protective helmet has at least two different connection types, wherein a component (14.1,..., 15.1,..., 16.1,...) on the supporting structure side can then be connected to a component (11.1,..., 12.1,..., 17.1,...) on the internal equipment side in order to produce a detachable connection between the supporting structure (3, 4.1, 4.r, 5, 6, 8, 10) and the internal equipment if the two components belong to the same connection type, and wherein a component on the supporting structure side cannot be connected to a component on the internal equipment side or the two components are not able to produce any connection between the supporting structure (3, 4.1, 4.r, 5, 6, 8, 10) and the internal equipment if the two components belong to two different connection types.