I had secured my Benq-Th681 with this bracket on the wall. With telescopic arm pulled-out, the holder rotates very slightly in skew, because the holder can not be mounted centrally above the projector (This is admittedly on the projector). The holder is not strong enough to compensate for the weight transfer, whereby the image can no longer be horizontally projected on the screen.
My review therefore refers specifically to my projector and wall mounting.