Being in engineering school, this is the tool that is fine for all my presentations, and even in the company in which I make my end of study.
Entertaining, but very effective and very practical with its standard AAA battery, and radio receiver that can be stored in the body of the pointer (no need to aim the receiver to switch slides as with an infrared receiver that can disturb the presentation because of instinct rather it is the projector screen as the receiver on the PC).
The only criticism is that to advance through the slides, you must press the button that will visually behind (personally, I reverse the arrows with Dole labels on the buttons (it's psychological, but it's better to me))
Really cheap for what it is !!!