The Heavy Duty Cathedral Ceiling Adaptor can be used with 1.5"-11.5 NPT extension columns (EXT, AEC models only) to securely mount and support a projector or flat panel display from an angled ceiling. This adaptor offers +95°/-5° of adjustment and includes a security slot for theft resistance. The ACC-CCPHD is a low-profile, secure solution to support nearly any projector or display in an angled ceiling application.