From verso of card: "This respirator is of stronger construction than the Civilian Respirator . . . and is intended for those who might have to work in the presence of gas and could not go to a gas-protected refuge room. . . . The face-piece is of moulded rubber, and is held in position by adjustable elastic bands passing round the back of the head; the eye-pieces are of strong glass. There is an outlet valve opposite the nose; the protuberance at the side of the face-piece can be used to fit a microphone for speaking on the telephone."