Dell PowerConnect 81 Serie Guide De Mise En Route page 19

Four-post Threaded Configuration
1 For this configuration, the flange ear castings must be removed from each
end of the ReadyRails assemblies. Use a Torx driver to remove the two
screws from each flange ear and remove each casting. See Figure 6, item 1
on page 17. Retain the castings for future rack requirements.
2 For each rail, attach the front and rear flanges to the post flanges with two
user-supplied screws at each end. See Figure 6, item 2 on page 17.
Figure 6. Four-post Threaded Configuration
Installation
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