These are the ones that can be upgraded to 3 or 4 monotors!The Humanscale M/Flex Dual Monitor Arm System M2.1 is a sleek and versatile desk mount designed to hold two monitors securely in place. The silver color and modern design make it a stylish addition to any workspace. With the ability to fit screens up to 32 inches and a VESA size of 100x100 mm, this system offers flexibility and convenience for organizing your dual monitor setup. The dual dynamic clamp mount ensures a stable and secure hold for your monitors, allowing for easy adjustment and customization of viewing angles.