LG AB-BL200X Owner's Manual page 15

7. Arrange the sets in a perfectly straight line using fixers so that sets do not stick out at the front or back.
(It is not necessary to use all the fixers.)
rly,
When you fix the screws, make sure that no set sticks out at the front or back.
8. Finally, remove all the module-protecting Cover on the outside of the sets.
<REAR>
Screw
(M4 x 10 mm)
15