Dell UPS 4200R - Manual (Page 9)

7 Installation and Startup |
3 Attach the rails to the rack:
Engage the back end of the rail until it fully seats on the vertical rack flange and the hook latch
locks in place.
Pull the rail toward the front.
Push the front end of the rail until it fully seats on the vertical rack flange and the hook latch locks
in place.
Installing the Cabinet
NOTE: Install the EBM directly below the UPS.
4 Slide the cabinet into the rack.