The Casio AD-E95100 LE power supply is the correct Casio adaptor for newer Casio keyboard models, including the SA-46, SA-47, CTK240, CTK1100/1300 CTK2200/ 3200/ 3400/ 4200/ 4400 and LK120. If in doubt, the way to tell - older models have white keys with a gap under them, newer models needing this adaptor have full fronts to the white keys.

Casio have a very unusual DC connection and non-Casio adaptors will usually have a loose fit giving a poor connection.

DC 9.5v 1A
Centre positive