Protective helmet

A protective helmet, comprising a main helmet part configured to cover a significant part of a user's head to protect the user's head in the case of accidents;

• and an additional inflatable element attached to said main helmet body and inflatable in the event of an accident so as to protect a neck of the user;
• and means for predominantly allowing expansion of said inflatable element in a direction away from the user's neck and preventing expansion of said inflatable element in a direction toward the user's neck, wherein said allowing and preventing means include a radially outer wall of said inflatable element which said radially outer wall is easier to expand, and a radially inner wall of said inflatable element which radially inner wall of said inflatable element is harder to expand, wherein said radially inner wall is thicker than said radially outer wall.