Active Workstation Legs: Designed for DIY tables, this ergonomic standing desk frame gives you the height adjustment you want with customization options (table top must be purchased separately) Compatibility: Recommended Tabletop Sizes - Length of 38' to 79', Width of 23' to 43', and a Thickness of 3/4' and greater (Actual Frame Length: 37.3 to 59', Frame Height: 23.8 to 49.4)