2 x  side support profiles to help support heavier monitors for All in 1 Gaming Freestanding Triple Monitor Mount With heavier monitors, there is always the possibiliy of a slight dip as the support beam is only attached on the inside. Side supports ensure that each of the side monitors will remain level with the middle monitor. *not compatible with wheel option   Includes: 2 x 1080mm 45x45 Profile 2 x Corner Bracket all necessary hardware for installation.