Simple and works! No batteries needed. Fits in shirt pocket. Perfect for lectures.
I teach college students computer programming. I use this pointer to point out and emphasize things on the projector screen better than using a mouse because the students see me walk to the screen and move my arms rather than look at their screens and try to listen while not looking.
This pointer is also good for pointing to computer screens when helping students with their programs. I can point while standing behind the student and without taking over the student's mouse or keyboard.
I recommend that you buy several of these just in case you lose it. I have one in my briefcase, one in my computer bag, and one in my drawer in my office. So far, I haven't lost one yet and I am getting good use of it during lectures and labs.