Push-ups already do a good bit of work on your triceps while focusing on the chest. But with one single change in our hand position, we can turn them into a mostly triceps-centric exercise.
Normally when you do push-ups, most of the work comes from your chest, but the exercise is versatile enough that just by putting our hands closer together, we can shift a lot of the load on the triceps:
When To Do Them
As said in the video, they work very well after you focused on the chest and want to lead over to the triceps. For example, if you do benchpresses and then flyes, the close-grip push-ups nicely lead over to triceps dips or a triceps isolation (kickbacks, triceps extensions etc.).
Alternatively, you could also do these as part of a bodyweight routine: regular or wide push-ups for the main chest muscle, declined push-ups for the upper chest and close-grip push-ups for the triceps.