We got the FotPro yellow ball with stability legs that is advertised as 26"/65cm for our son who is about 5' tall and 75-80 pounds, so that's what I'm reviewing.My son's 4th grade class uses these, and they come highly recommended by his teacher. When we first visited the classroom immediately before school started last year, we were a little skeptical. She told us that they improve posture and increase focus, particularly for kids who tend to fidget (which accurately describes my son). After talking with him about it over the next few months, we decided that maybe it would help him at home too, so we got this one for his birthday last month. It turns out that these are the same brand they use in the classroom.The instructions for blowing it up the first time aren't as simple as "fill it up with air" and they should obviously be followed carefully.We also asked my son what the rules were in the classroom, and he said there are only two:1. Keep your feet on the floor.2. If you can hear your bouncing, you're bouncing too hard.These balls aren't toys, and those two simple rules seem to cover everything.We think it's been awesome for use at home. Our son seems to be able to better focus on school work when he can "bounce" -this way he's not tapping, picking, or otherwise doing things that aren't conducive to school work. (And every little bit helps!)For the record, I'm 5'2" and about 105 pounds. I considered getting one of these for myself to use at the office, but I find that it's a little too low for me. This might be because it's time to add air or just because I'm so short. (Remember that children's desks are lower than a standard 30" desk or table.)Well worth what we paid for it.
