Kimex 031-1026 Manuel D'installation page 7

Position the sliding nuts as shown, making sure that the distance
shown in the illustration matches that of the two columns. You
may need a tape measure to complete this step.
Align the mounting holes on sliding nuts to the holes found on the connecting plate
Attach the assembled columnb to the Mounting rails (A) with screws (G)
Use the tape measure to make sure the position of the mounting rails is parallel
3. Assemble the equipment shelf
Attach the support brackets (F) and (E) to the backside of the equipment shelf (B))
Insert 2 sliding nuts (C) into the top slot of the bottom mounting rail and 2 in the 2nd from top slot
as shown
Position the nuts next to the support brackets as shown in the right figure
Fix the nuts using screws (H)