Recommended Minimum Wall Area Dimensions; Figure 24: Minimum Wall Area Dimensions For The At-Gs924Mx Switch With The Front Panel On The Left - Allied Telesis AT-GS924MX Installation Manual

Recommended
Minimum Wall
Area Dimensions
The wall location for the AT-GS924MX Switch must provide adequate
space to the front and back panels so that you can service the unit, and for
ventilation. The recommended minimum dimensions for the reserved wall
area are listed here:
Width: 54.0 centimeters (21 1/4 inches)

Height: 43.2 centimeters (17 inches)

You should position the switch in the reserved wall area such that the front
panel has more space than the rear panel. This may make it easier for you
to service and maintain the unit. Figure 24 and Figure 25 on page 70
illustrate the recommended positions of the switch in the reserved area
when the front panel is on the left and right, respectively.
Figure 24. Minimum Wall Area Dimensions for the AT-GS924MX Switch
with the Front Panel on the Left
AT-GS900MX Series Installation Guide for Stand-alone Switches
69