Mitsubishi Electric LCPU-U-HW Safety Manuallines page 44

(Right side)
POINT
Do not slide modules from the edge of the DIN rail when mounting. Doing so may damage
the metal part located on the back of the module.
DIN rail
stopper
DIN rail
43
9. Attach a DIN rail stopper on
the right of the module with the
same procedure.
Install the stopper upside
down for the right side.