IBM NeXtScale System Planning And Implementation Manual page 145

The following features also are included:
A front stabilizer bracket, which can be used to secure the rack to the floor, as
shown in Figure 5-6.
Bolts
Stabilizer bracket
Figure 5-6 Rack with stabilizer bracket attached, being bolted to the floor
As shown in Figure 5-7 on page 128, a recirculation plate is used to prevent
warm air that is coming from the rear of the rack from passing under the rack
and into the front of the servers. This is not required if the stabilizer bracket is
installed.
127
Chapter 5. Rack planning