Yes4All Aerobic Exercise Workout Step Platform Extra Risers - Health Club Size with 2 Adjustable Risers

Very stable. Gave me the extra height that I needed to feel challenged.

Each one adds two inches of height to the step. Stable platform, light and easy to stack and move.

I have a yes 4 all aerobic stepper platform which came with 4 of these spacers. The platform height is originally 4-8 inches but I seem to be outgrowing it and I wanted to add another height level (10inches). For that purpose I purchased this pair and it fits perfectly with the rest of the kit. Now my height range is 4-10 inches which is a lot more flexible. It is the same material and quality as the ones that came with the kit. For stability purposes I would not go above 10 inches though. Instead if you need something higher, consider purchasing a plyobox. Until then, this does the job.

Nice riser for the squat platform. I started using it for step ups and weight training . The lift is the trick

They do what they're supposed to.