The 3/4" pipe reducer is required for use with the 3/4" extension column and any of the Peerless projector mounts which are designed for 1 1/2" extensions. The 3/4" extensions are a less bulky alternative to the standard 1 1/2" pipe.
Two pipe reducers are necessary for using the 3/4" pipe, one reducer for each end (one for the ceiling flange and one for the mount itself).
The 3/4" extension pipes will work with an appropriate Peerless projector mount with 1 1/2" fixtures if and only if they are coupled with the 3/4" pipe reducer.
Installation Instructions
Technical Data