I was looking for a footstool that kept my foot straight regardless of what height it was set to, In other words, not having your toes higher than your heel when resting on it as I found that quite uncomfortable.
This footstool does excactly that - your foot is level. Also, it weighs very little.
Note that it is short but that is not an issue for me (my foot is size 9 or 10 in UK size).
The feet is made of hard plastic and hence why people find it slipping on a wooden floor (and I deducted a star). Why didn’t they use rubber?! But had no experience of it slipping beneath my foot - I have had it for one day. Extremely pleased with the product and are super happy with it.