Wall Mount: The dual arm can be mounted on concrete/brick walls only, helping you to fix two screens at the same time. Compared with a straight wall, the curved design of the arm can optimize the visual limitation on the basis Horizontal Adapter Arm: The dual arm also can convert a single monitor mount into a dual monitor mount with the middle Mounting Holes plate. One thing needs to check is your existing mounts hole pattern is 75mm or 100mm