A face mask assembly for supplying breathable gas to a wearer, said face mask assembly comprising: a mask frame (1512), a facial cushion (16) attached to the mask frame, a forehead support (101), said forehead support including a forehead cushion assembly (1551, 1552), and an adjustment knob (1550) operatively coupled to the forehead cushion assembly by a threaded shaft (1522), wherein turning movement of the adjustment knob causes the forehead cushion assembly to be moved between a retracted position and an extended positions.
