L1(left side): Backrest Lock Knob: Rotate the knob counter-clockwise and lean back on the backrest to allow the backrest to recline freely.
L2(left side): Forward Tilt Function Handle: Pull the handle up and down to move the backrest forward.
R1(Right side): Backrest Tilt Tension Adjustment Knob: Turn clockwise/counterclockwise to tighten or loosen the tension of the backrest tilt.
R2(Right side): Height Adjustable Handle: Push the handle up to adjust the height of the seat.