A few weeks ago I spent the day sewing with my Wild Thread friends. A local church allows us to use their space and it is always a great day spent chatting, eating, and of course sewing. I noticed my friend Pat sitting on one of these. I had never seen one before. She let me use it for a while and I loved it so much as soon as I got home that night I ordered one.
Here is the product description: Place the softly inflated disc in your chair to prevent fatigue, reduce pressure on the tailbone and help to relieve lower back pain, while strengthening core muscles and improve posture. Place smooth side down. The knobby texture allows air flow for cooler seating and promotes improved blood circulation. Air filled and will stay soft and comfortable. Can be used in hard or soft chairs, recliners, car seats or anywhere you sit for long periods of time.
PS. I am not being endorsed - I just love it! :)