Serious, but not too heavy for VP

For construction, it's solid. Not to say.
But for the rest .... It lacks the M5 screws to some projectors (like my Sony) and you need a good big screwdriver to tighten the screws (see a small ratchet with mouthpiece that goes well).
When small fixing screws for ceiling prefer lag, at least!

If I put for "VP not too heavy," that is not to question the strength of the support, but for a level control virtually impossible. Or, go for spring washers or fan to facilitate this. Do not hesitate to put for fixing the VP (video projector). Small vibrations due to the fan could loosen. See a small tube of "thread lock" not too strong.

Clearly, for my big Sony SXRD is not the top. It's too "elastic", not rigid enough. The slightest focus setting, zoom or lenz Shift makes you "vibrate" in every sense.