Automatic dual 3-D tracing Variable fulcrum stylus Composite tracing Advanced shape editor function Multi-function lab tracer and web tracer Detailed Information Automatic dual 3-D tracing Automatic dual 3-D tracing The unique 3-D mechanism digitizes a binocular measure of 1,000 points of reference per eye. The highly accurate digitized data assures a precise first time fit, regardless of the level of frame curvature.