BenQ ZOWIE RL2455S User Manual page 18

Extend the monitor to the maximum extended position.
-90
Then tilt the monitor. And rotate the monitor 90
degrees counterclockwise as illustrated.
You might want to adjust the monitor stand height. See
Adjusting the monitor height on page 20
for more
information.
You should position the monitor and angle the screen to
minimize unwanted reflections from other light sources.
18 Assembling your monitor with a height adjustment stand