You can mount most monitors onto an arm, but you need to make sure you buy the right monitor arm. The majority of monitors are mounted via a universal mount known as the VESA mount. Compare the pattern of mounting holes at the back of your monitor with the VESA mount and see if the pattern matches. All Desky monitor arms (unless specified) are designed to work with VESA mounts and are VESA-compatible.
However, some monitors such as iMacs, for example, do not use the VESA mount. We also sell an iMac monitor arm designed to work perfectly with the iMac turning it into the ultimate adjustable monitor. It's also a good idea to check the weight capacity of the monitor stand you're purchasing to ensure your monitor isn't too heavy. Finally, if using a dual monitor stand, check your screen size doesn't interfere with movement.