FLEXIBLE MOUNTING: Our single monitor mounts are available in two mounting options, either using the "E" shaped clamps to secure it to a tabletop from 0.39 inches to 2.36/3.96 inches thick, or selecting the grommet holes to secure it to a tabletop from 0.39 inches to 2.36/3.96 inches. Please note that if you wish the bracket to rotate, carefully tighten the bracket, but do not tighten until it is fully secured, 50% tightening is recommended.