PHOTONIK retro-reflector is a trihedral prism manufactured from fine BK7 optical glass. Three total internal reflections send a fully inverted reflection of the input beam or image backwards toward the original direction. This reflection is parallel to the input beam or image, making the retro-reflector useful in applications involving beam alignment and beam delivery. The insensitivity of the prism's physical orientation ensures that even when the beam or incident light enters the prism off its normal, there will still be a 180-deg inverted reflection.