A respiration system includes a pressure regulator including a housing, an inlet for connection to a pressurized gas comprising oxygen, and a first data communication system, and a respiration facepiece including an interface to which the pressure regulator is removably attachable, at least one seal system to form a sealing engagement with the face of a user to encompass the nose and mouth of a wearer; an inspiration port in fluid connection with the pressure regulator interface and in fluid connection with the interior of the facepiece and at least one display within a volume of sealing engagement with the face of the user that is within the field of view of the user. The pressure regulator interface includes a second data communication system to receive data from the first data communication system to control the at least one display. A sealing attachment may, for example, be formed between the pressure regulator and the interface of the facepiece.