The Rocelco VADRB-43 Height Adjustable Sit to Standing Desk Riser and Comfort Floor Mat Bundle offers the versatility you need to get through your work day. Now you can sit part of the day or stand to take advantage of all the health benefits that come with standing and moving around. With the R VADRB-43, you and your associates will become healthier and more productive. It fits over your current desk with no need to buy additional furniture. With its spacious 42.9" W x 20.5" D work surface, you can hold up to 2 large monitors, a laptop, and more. It also includes an extra large keyboard tray that measures 34.8" W x 10" D that is an ergonomic 4" below the desktop. Quick-disconnect keyboard tray allows portable use. EVR Enhanced Vertical Range rises up to 21.7" and down to 4.7", to optimize the ergonomic work position for people of all heights. Straight up and down motion minimizes required depth (18.5"). Gas piston assist allows you to easily raise and lower up to 33lbs. 10.5" wide slot holds tablet or phone. Desk riser is fully assembled and ready to go! The The included MAFM Anti-Fatigue comfort floor mat is designed to work in tandem with standing desk risers. It will help support your back, hips, knees and feet so you can get all the benefits of standing while you work. This versatile desk mat effectively ?reduces" your weight by 30% to make standing easier on your feet and joints. The advanced multi-layer construction offers a comfortable ?leather like" top surface, a memory foam inner layer and a non-slip bottom. A perfect 30" x 20" size provides plenty of room to move around, but still can fit into the kneehole of a standard desk or built-in when it is not being used. Beveled edges help to reduce tripping issues and ?" commercial grade thickness provides hours of comfort and stability. The durable materials on this desk mat will not break down, even after years of use.