If you search for other quad monitor mounts, though, Secretlab's offering ... and rotation adjustability as Secretlab's ...

Even if you don't need to move your monitors into different positions, the gain in desk space alone makes monitor arms ...

The Secretlab MAGNUS Vertical Monitor Stand lets you mount up to four screens simultaneously in one dynamic package.

Fits for Ultrawide Monitors up to 43" - Premium Dual monitor desk mount fits most of flat or curved computer screen up to 43" and hold 2.2 lbs to 37.5 lbs each monitor arm ,compatible with VESA ...

grommet mount attaches through a surface hole to desks up to 2.25 inches thick Improved comfort: Easily raise your monitor up to 17.3 inches above your worksurface with 13 inches of lift ...

The monitor arm mounts at the back of your desk ... Also, don't limit yourself to one arm on your desk. Dell makes a dual-arm set, and I've gone up to having seven arms on my desk at once!

The Secretlab Magus Vertical Monitor Stand can hold anywhere from one to four displays, optimising multi-screen productivity ...