Height Adjustable VESA Adapter: Attach this adapter to your current mount or stand to give you an increased 6.25' of height adjustment (3.25' up and 3' down from center). 3 Mounting Configurations provide 4 (2 up and 2 down) of additional adjustment Compatibility: Designed for 13' to 27' monitors up to 17.6 pounds with VESA 75x75mm or 100x100mm back side mounting. (Note: Monitor mount must have 75x75mm VESA compatibility)