I am very impressed with this concept. I have used exercise balls as desk chairs for several years and this addresses two of the three issues I have with them.
The first being they are too “squishy” and do not provide the right amount of support regardless of size/pressure. A larger ball may be the right height but not firm enough and a smaller ball is too firm when pumped to an adequate height.
This fixes the issues I had as the cover constrains the expansion of the ball and provides the necessary needed support that was missing.
The second issue that is resolved is you no longer get a hot seat from being in constant contact with a non-porus plastic surface. The felt “breathes” enough to make sitting comfortable over extended periods of time. I was initally concerned that the exposed seams may be uncomfortable, but that has not been the case in my last month of daily use.
The third item (which I have a simple fix for) is that the balls like to run away across the room every time you get up. Here is what you do: go to WM and get a container of copper BBs (1500 ct). Use the integrated funnel on the cap (you will have to cut with scissors to fit) and pour them in very slowly through the air vent. Now for under four dollars your ball will be well-behaved without adding much weight.
” – Carpemanana – Amazon Customer

See this exact review and more on our Amazon listing!