Which reinforcement spacer for exposed concrete?

Which reinforcement spacer for exposed concrete?

This question keeps coming up on many exposed concrete construction sites for exposed concrete classes 2 to 4.

In this video, I provide a brief overview of which spacers are suitable for exposed concrete and which ones tend to cause defects in the finished surface.
I also present in this video the wall reinforcement spacer that I consider to be one of the best for producing high-quality exposed concrete walls.

Last but not least, a note on the recommended procedure outlined in the exposed concrete guidelines.