Does the job with no problems.

Sturdy and easy to fix on table edge / shelves provided the edge has the necessary free space.

I gave it 4 stars because a more elegant design for the clamp would be nice. It's solid and simple as it is, but it takes up a fair bit of space below the clamping point. That's because it's designed to fit a wide range of dimensions, but in my case it protrudes more than necessary and can sometimes get in the way.