I forgive also full marks because the unit meets all the requirements that I had. Once you have connected the USB receiver, the Presenter is installed after two to three clicks. I immediately called a PPT and everything went smoothly, even through a thick wall he has scrolled. It is comfortable to hold and easy to operate, so you can concentrate on the presentation intuitively in the dark. Even people with big hands will get along well with the part, the buttons are far enough apart. The functions are limited to the essentials: scroll up and down, laser pointer (red) and dark screen. Starts the presentation from the computer out. Who additionally need other functions and rely on accurate timing (vibration every 5 minutes, time display etc.) is the be the equipment recommended by Logitech. I would buy the unit back in any case! PS: my cat had fun at the laser :-)