Yutai Corner Cubes are designed to reflect any ray or beam entering the prism face, regardless of the orientation of the prism, back onto itself. Yutai Coner Cube have three mutually perpendicular surfaces and a hypotenuse face. Their accuracy is shown with the angular deviation (parallelism) between input and output beams. It depends on the mutual perpendicularity of the trihidron surfaces. Yutai Corner Cubes are used to the optical metrology, gauging and laser interferometer.