The lasers which are used in the F5000 and F3000 are both used to help in the quick alignment of the beams. They are a guide for the alignment of the Infra-Red signal. Note: do not look directly at the laser.
F5000: The laser is guided onto the Reflector(s) by the user by means of the Up, Down, Left and Right buttons on the System Controller. This ensures that when the Automatic Infra-Red Self Alignment takes place, the Detector is pointing directly at the Reflector(s) and so the Detector will align onto the Reflectors.