Dell PowerEdge C6220 - Manual (Page 6)

Getting Started With Your System | 4
1 Push on the latch release buttons on the end piece midpoints to open
the rail latches. See Figure 1.
2 Align the end pieces of the rails on the vertical rack flanges to seat
the pegs in the bottom hole of the first U and the top hole of the
second U. See Figure 1.
NOTE: The rails can be used in both square-hole (item 1 in the following figure)
and round-hole racks (item 2 in the following figure).
Figure 1 Pushing the Latch Release Buttons
NOTE: To remove the rails, push on the latch release button on the end piece
midpoint and unseat each rail.