The Rocelco R DADBR-40 Height-Adjustable Sit-to-Standing Desk Riser offers flexibility to switch between sitting and standing, promoting health and productivity. With a 40" W x 23.6" D work surface, it accommodates up to two large monitors, a laptop and more. The retractable keyboard tray (25.5" W x 11.25" D) is ergonomically positioned 4.5" below the desktop for comfort. The EVR Enhanced Vertical Range adjusts from 5" to 20" to suit users of various heights, with a straight up-and-down motion that minimizes desk depth (23.25"). A gas-piston assist allows easy height adjustment and accommodates up to 40 lb. Included Rocelco MA2 - Double-Monitor Arm with GPCMA (Gas Piston Counterbalance Motion Assist) allows effortless independent screen adjustment for comfortable viewing. It fits two 13"-27" screens up to 14.3 lb. each. This desk riser includes USB 3.0 and USB-C multimedia ports to conveniently connect and charge your devices. Cable channels provide a hassle-free way to run your cables and maintain a tidy, uncluttered work space. Desk riser includes two mounting systems to attach to your desk - clamp and grommet.