As part of the Professional Series, this Premier Keyboard Tray features the Comfort-Lift system that lets you slide mouse platform left or right over keyboard numeric pad and offers two custom-height positions. Mouse platform tilts forward or backward, adjusts up or down to height of keyboard, and mounts on left or right side of keyboard. Warning Trak helps prevent your mouse from sliding off mousing platform. Lift and lock feature lets you adjust height with one hand - tilt platform to reposition and then straighten to lock in place. Single manual knob adjusts tilt up to negative 10 degrees for optimal comfort. Health-V memory foam wrist supports with Microban antimicrobial protection stay cleaner and relieve wrist pressure to help prevent carpal tunnel syndrome.