The DADR Standing Desk Converter Bundle is the perfect way to get your ergonomic workstation started. It comes with a Rocelco DADRT-40 Sit to Stand Desk Riser and a Rocelco MAFM Medium Anti Fatigue Mat. The DADR-40 Height Adjustable Sit to Standing Desk Riser and Converter 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 DADR-40, 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 40" W x 23.62" D work surface, you can hold up to 2 large monitors, a laptop, and more. It also includes an retractable keyboard tray that measures 25.625" W x 11" D that is an ergonomic 4.5" below the desktop. EVR Enhanced Vertical Range rises up to 20" and down to 5", to optimize the ergonomic work position for people of all heights. Straight up and down motion minimizes required depth 23". Gas piston assist allows you to easily raise and lower up to 40lbs. Grommet hole allows you to route cables or add an optional single or dual monitor arm such as the Rocelco DM1 or DM2. It works with your existing desk or create a complete standing desk with the optional Deluxe Floor Stand DADR-FS. Fully assembled and ready to go The Rocelco MAFM Anti-Fatigue Mat is designed to work in tandem with the standing desk riser. It will help support your back, hips, knees and feet so you can get all the benefits of standing while you work. This commercial 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 the ¾" commercial grade thick desk mat provides hours of comfort and stability. The durable materials on this gel desk mat will not break down, even after years of use. The ¾" commercial grade thick desk mat provides hours of comfort and stability. The durable materials on this gel desk mat will not break down, even after years of use.