Transform your desk into a versatile ergonomic "Sit to Stand" system for the healthful benefits and productivity of working while standing. Desk riser sits right on top of desk. Advanced gas-assisted lift system offers continual range of height adjustment up to 20" off the desk. Desk riser provides full stability at all height positions. Large platform holds two 24" monitors. Desk riser intrudes little into the work space and floor space. It also includes a repositionable keyboard tray for optimum comfort. Grommet hole centered near the back edge lets you mount optional monitor arms (sold separately) for single and double monitor.