Acer AT310 F1 - Manual (Page 134)

Appendix B Rack mount configuration 116
4 Install the server in the system rack.
(1) Insert the inner rails attached to the server into the mounting
rails.
(2) Push the server into the rack until you hear a click sound.
Caution! To avoid personal injury, care should be taken when
pressing the inner rail release latches and sliding the component
into the rack.