Acer Altos G710 - Manual (Page 164)

Appendix B: Acer Altos G710 rack installation guide 154
Caution! To avoid personal injury, care should be taken when
pressing the inner rail release latches and sliding the component
into the rack.
12 Attach the cable arm to the system by following the steps below:
The optional cable carm allows you to tie-wrap all cables to and
from the system. As you slide the system in and out of the rack, the
cable arm collapses and extends, keeping the cables untangled
and attached to the system.