We got our kid a Bamboo tablet/pen some years ago and she
has used it. She draws a lot with it. Been a very good thing for her.
It's a good size to...I think about 8"of active area.
CTE640 - couldn't find it but found
CTE450 which is a much smaller active area.
The keyboard has a led battery level indicator. I charged it when I got it, a few weeks ago
and I haven't charged it yet and still indicates 3 bars of 3.
I think that sensor for the lights is sure helping.