Panasonic KX-DT390 Quick Reference Manual page 3

To lower:
Raise the operation board to level 8. Next, with one hand on the
base of the unit, lift the operation board again to release the latch,
then slowly push the operation board down to level 1. If the
operation board cannot be lowered to level 1, repeat this step.
1. Fit the protrusions on the
KX-DT390 and a DPT into the
4 holes on the plate
(included).
Operation Board Angle Adjustment
2. Attach the plate with the 4
screws (included).
Attaching a DPT
3