Although only 25 to "specified, it keeps my Acer 27" monitor with no problems. But I think that the weight is especially crucial. My monitor weighs just ridiculous 3Kg.
I have no problems with without saying leaning to angle or the like. Once installed and set, and the thing will not budge.
Furthermore, the mount is also very narrow (see photos) which of course brings an enormous space savings. That was also the reason why I have decided that holders of Acer are 1. not adjustable in height and 2. they take far too much space.
the holder can highly recommend, for this price you struggle to find a comparable product.
Price / performance ratio are unbeatable here.