Many kickboxing studios and cross fit studios use these jump boxes for exercise. They are made in such a way to offer 3 heights and they can be changed as necessary.
Unlike the cheap junk you can find online these are made of hardwood plywood such as Birch or Maple and are fully brandable with whatever logo or symbols you choose.
Each side has the height that the user will be jumping onto and each surface is sealed with several coats of a gloss polyurethane.
Typically 20" and 24" and 30"
As you can see they are also available with the corner bumpers as well if you are using this on a slippery surface.