IBM AA-RWF3A-TE - Manual (Page 44)

4. Assemble the outer rails by completing option a or option b:
a. Attach the left outer rail and the right outer rail to the rear mounting brackets
using two 1/4-20 hex nuts with captive star lock-washers attached loosely,
as shown in Figure 12 . Do not tighten the nuts until completing the steps in
Securing the switch to the outer rails , page 50.
Figure 12 Installing the outer rails (HP 10000 series racks)
44 Installing and configuring SAN Switches