Put Al and A2 parts of the terminal on the screw head and press them down to hold.
4) It will be seen as followings after the installation.
Screw required
to fix the bracket
to the wall.
The backup battery is built-in within the WLL terminal so that it can operate without external
power for some time. If the SMPS is removed, the backup battery starts to operate. It can be used
about 15 hours in stand-by mode and two hours during the call.