Paint paperless, practice math, leave messages… Captions are possible with the enclosed pen or fingernails. The surface of the display is pressure sensitive, i.e. the tighter you press, the thicker the stroke. Press the clear key again to get a blank display. The replaceable battery can be used for about 50,000 deletions. After applying the self-adhesive magnetic strip, the writing board adheres to all magnetic surfaces. Supplied incl.1 button cell 3V CR2016, color: black, size approx.: 14.3 x 0.4 x 21.9 cm.