Additional Ceiling Plate for PCMD Projector Mounts with a Lateral Shift Coupling -- Additional Ceiling Plate with a Lateral Shift CouplingThis additional ceiling plate will allow you to easily relocate your projector to another room without disturbing the ceiling fixture. The Lateral Shift Coupling allows 1-1/2 inches of left/right lateral adjustment to center the projector lens. The Lateral Shift Coupling is ideal for installations where the mounting surface is not perfectly aligned with the center of the screen.