There is only one thing I don't care for and that is strictly on me. I have sensitive feet and the little knobs on the top are a bit uncomfortable - so I wear socks and that helps. This stability disk is definitely superior to others I have tried. Upon arrival it will need a little more inflation, so don't forget to order an inflation device if you don't have one.
This disk came nicely packaged, and filled partially with air. It does NOT come with a pump to fill it up if one needs it to be a little fuller; however, a simple bike pump works. I filled it a little more because I bought it to sit on at my computer, so I sit up straighter. I have only used it one day, but do far it is very comfortable and supports my core well.
I purchased two of these to continue my physical therapy at home. They say you can inflate with a bicycle pump, but it was extremely hard. You would be better to do it with an air compressor.
This purchase was for my mom, who tried mine while visiting. I've had mine - same brand - for 4+ years.This disk does what I wanted. The size is fine for my under 5'5" frame, The plastic is thick and even pets trampling it for years hasn't harmed it. I haven't felt the need to add air to it.I use it almost daily to keep my ankles and an ACL-less knee in top shape. It's propped next to my office desk, and while reading email or watching TV, I stand up and do one-legged balancing for a minute each side, 5-10 times. Most times I keep my knees slightly bent, but sometimes I lock the knee, and concentrate on strengthening the ankle. The desk is right there if I wobble.I haven't used it for any other exercises, but I notice my knees/ankles don't like it when I go without it for longer than 4-5 days.