Projector adaptor plates that are either universally compatible with most projectors, or uniquely compatible with one projector make or model. Peerless-AV adaptor plates for projectors allow users to choose between Peerless-AV' wide array of applications and accessories to mount a projector anywhere. Most models feature security fasteners for theft resistance, and flip-down hinges that allow easy access to the projector for maintenance, cleaning, etc.