The pervious 2 answers are not entirely accurate. Although this type of VESA mount is not compatible with the 21.4" iMac you can in fact buy one designed for the iMac 21.4" and the existing attached leg mount does in fact come off. Youtube it and you will find that there is a hidden notch behind the attached leg to the iMac which can be released to expose the 8 screws to detach the leg mount and attach a VESA mount.
Not everyone on here will give you the most accurate answer but Google it and you can find what your looking for and usually for under $20. I did it myself and works great.
- Answered by Adam N from Glenwood
- 14 Jun 2018
- Flag as inappropriate Answer (is there a VESA mount for a 21.5" iMac?)