12. OPERATION F : Adjusting height of headrest Move the headrest up and down to the desired height. The adjustment range is 50 mm (2.0 in). G : Adjusting headrest angle Rotate the headrest to the front or rear. H : Adjusting angle of armrest Adjust the angle of the armrest by rotating knob 5 . The adjusting range is 30° (Forward tilt: 25°, Backward tilt: 5°). Also, when the armrest is turned, it will spring up. I : Lumbar support The tension of the waist part can be adjusted by turning grip 6 . 2-45