Using (
),You can swivel the monitor left and right at an angle of 350° to set the monitor lengthwise. The rubber under the stand is to avoid the monitor slide. 
When you try to rotate the monitor in the state of the power cord or cable connecting to the monitor, the power cord of cable can be destroyed.
Tilt angle
Using (
), You can adjust the tilt anlgle within a range of
Pivot Stand / HAS Stand