The SPVESA38MM adapter plate allows a VESA-compatible flat panel monitor, television, or other device to be connected to the mount of your choice (Mounts, mount arms, double socket arms, holders, and devices sold separately.) This unique adapter plate measures 4.75 inches (121mm) square and includes VESA 75 (75mm x 75mm) and VESA 100 (100mm x 100mm) as well as other pre-drilled patterns. The 38mm rubber ball is positioned off center for ease of use. Use with Arkon's 38mm Robust Mount Series shafts or RAM Mounts Size C double socket arms.