A system, comprising: a pressure regulator (400, 400a) comprising a housing and a rearward extending section extending rearward from the housing, a sealing member (460a, 460) positioned on rearward extending section, and a first energy transfer element (480A', 480a, 480b, 480c, 480d) positioned on the rearward extending section, wherein rearward refers a direction associated with a person when the system is worn by the person; a facepiece comprising a lens, at least one seal system connected to the lens which forms a sealing engagement with the face of a user to define an interior volume encompassing the nose and mouth of the user; an inspiration port in fluid connection with an interface port of a pressure regulator interface for entry of pressurized air from the pressure regulator (400, 400a) into the interior volume of the facepiece, and a first cooperating energy transfer element (290A', 290a, 290b, 290c, 290d) positioned within the pressure regulator interface such that the first cooperating energy transfer element (290A', 290a, 290b, 290c, 290d) aligns with the first energy transfer element (480A', 480a, 480b, 480c, 480d) to transfer energy via contact of first cooperating energy transfer element (290A', 290a, 290b, 290c, 290d) and first energy transfer element (480A', 480a, 480b, 480c, 480d) or via wireless transmission of the energy between first cooperating energy transfer element (290A', 290a, 290b, 290c, 290d) and first energy transfer element (480A', 480a, 480b, 480c, 480d) for transmission of at least one of data or power; a sealing member (460a, 460) positioned on the rearward extending section forming a sealing engagement between the rearward extending section and an inner wall of the interface port, the sealing member (460a, 460) being positioned on the rearward extending section so that each of the first energy transfer element (480A', 480a, 480b, 480c, 480d) and the first cooperating energy transfer element (290A', 290a, 290b, 290c, 290d) are sealed from the external environment by the sealing member (460a, 460), the first energy transfer element (480A', 480a, 480b, 480c, 480d') being configured to be operatively connected with a system exterior to the facepiece; and a system inside the interior volume of the facepiece in operative connection with the first cooperating energy transfer element (290A', 290a, 290b, 290c, 290d). a pressure regulator (400, 400a) comprising a housing and a rearward extending section extending rearward from the housing, a sealing member (460a, 460) positioned on rearward extending section, and a first energy transfer element (480A', 480a, 480b, 480c, 480d) positioned on the rearward extending section, wherein rearward refers a direction associated with a person when the system is worn by the person; a facepiece comprising a lens, at least one seal system connected to the lens which forms a sealing engagement with the face of a user to define an interior volume encompassing the nose and mouth of the user; an inspiration port in fluid connection with an interface port of a pressure regulator interface for entry of pressurized air from the pressure regulator (400, 400a) into the interior volume of the facepiece, and a first cooperating energy transfer element (290A', 290a, 290b, 290c, 290d) positioned within the pressure regulator interface such that the first cooperating energy transfer element (290A', 290a, 290b, 290c, 290d) aligns with the first energy transfer element (480A', 480a, 480b, 480c, 480d) to transfer energy via contact of first cooperating energy transfer element (290A', 290a, 290b, 290c, 290d) and first energy transfer element (480A', 480a, 480b, 480c, 480d) or via wireless transmission of the energy between first cooperating energy transfer element (290A', 290a, 290b, 290c, 290d) and first energy transfer element (480A', 480a, 480b, 480c, 480d) for transmission of at least one of data or power; a sealing member (460a, 460) positioned on the rearward extending section forming a sealing engagement between the rearward extending section and an inner wall of the interface port, the sealing member (460a, 460) being positioned on the rearward extending section so that each of the first energy transfer element (480A', 480a, 480b, 480c, 480d) and the first cooperating energy transfer element (290A', 290a, 290b, 290c, 290d) are sealed from the external environment by the sealing member (460a, 460), the first energy transfer element (480A', 480a, 480b, 480c, 480d') being configured to be operatively connected with a system exterior to the facepiece; and a system inside the interior volume of the facepiece in operative connection with the first cooperating energy transfer element (290A', 290a, 290b, 290c, 290d).