Sony Ericsson Dialog 4223 - Manual (Page 122)

Installation
BusinessPhone – Dialog 4223 Professional / Dialog 3213 122
Dialog 3213 Executive
Install cables
1 Cable to handset
2 Cable to exchange
3 Space for personal directory list (optional)
4 Wall mounting screw holes
You can put the cable to the handset in any of the two notches
underneath the telephone. The cable to the exchange has to be
plugged in LINE.
Change cables
To remove a cable, push down the plug stop. Use a screwdriver to
unlock the stop.