HEIGHT ADJUSTABLE: The sliding keyboard tray clamps feature three height settings (3.9, 4.7, and 5.5 in) from the desk surface to the tray. This black clamp-on keyboard tray provides a large area (27.5x12.2 in) that supports up to 26.5 lb EASY TO INSTALL: Once assembled, the keyboard drawer is secured by tightening the clamps by hand. The clamps have anti-slip pads for stability and to protect the desk surface. Each clamp uses very little space, 1.8x2.5 in. For desks up to 2.3 in thick EFFORTLESS USE: The under desk keyboard tray features sliding rails for easy access, and the curved edge protrudes 0.6 in to adjust the tray when needed. The front of the keyboard and mouse tray extends up to 8.5 in from the edge of the desk COMFORTABLE: The front edge of the keyboard pull out tray is ergonomically curved for wrist comfort. In addition, the 0.15 in lip on the back of the keyboard holder helps prevent any equipment from falling off the edge THE IT PRO'S CHOICE: Designed and built for IT Professionals, this TAA compliant ergonomic keyboard tray is backed for 2-years, including free lifetime 24/5 multi-lingual technical assistance