Smooth movement slide-out tray puts your keyboard right where you need it, under your desk for improved ergonomics. Easy to install with sturdy metal clamps on any surface up to 1.5" thick. No screw installation does not damage the work surface. Impact resistant, plastic tray fits most standard and ergonomic keyboards. A great choice when under-desk crossbars, hardware, or other obstructions make permanent mount keyboard trays impossible to install.