1. Sturdy CClamps Attach the keyboard tray or any extension board to your workstation with sturdy Cclamps that hold everything tightly in place and are easily adjustable for user convenience. The sponge pads help to avoid causing any damage to your desk (1.9' Maximum Desk Thickness). NOTE: before purchasing, please make sure that your desktop does not exceed 1.9' in thickness. 2. Foldable Design to Maximize Desk Space 90° foldable storage design enables you to slide in the keyboard tray under the desktop instead of placing it on the desk while not in use, saving valuable space on your workstation. NOTE: Please check whether the desk type is suitable before purchasing. 3. High Loadbearing Capacity Reinforced and thickened Kshaped alloy movable bracket, which conforms to the mechanical structure, can hold up to 661lbs. This multipurpose desk arm tray bracket can serve for arm rest, shelf, desktop extension board, computer mouse pad and equipment support, etc. 4. Easy and Fast Installation The desktop bracket is preassembled. In most cases, all that you need is to tighten the four screws which only takes a minute before it is ready for use. The manual knob supports fast installation and disassembly, realizing multiscene conversion and use. Nonhole installation ensures that the desktop is undamaged.